Well, I ahve no experience with J&D, so I cant help there, but I have plenty of knowledge of the R&C series and have played through ToD and CiT. Given that most of the designs that we are using are the most recent (Prince of Persia, Nightmare, etc), Id say giving Ratchet and Clank a selection of weaponry from the Future Series (Tools of Destruction, Quest for Booty, and Crack in Time), as well as possibly giving Clank some tools from Secret Agent Clank, a relatively recent game starring Clank.
Ive created a balanced list of weaponry and gadgets that they both could viably use IRL (some of this stuff is just a bit too crazy for the Future Tech clause) and have thought of hte real-world applications for. Get ready for a bit of in-depth analysis:
Ratchet
Omniwrench Millenium 12- Wrench for one-handed combat and mechanical use. Proficient usage of wrenches as weapons has been seen throughout hte Ratchet and Clank series. Made of strong metal material able to damage robots and battle armor.
Combuster - Relatively small firearm, size of a small rifle, light, fires globs of extremely hot liquid distances of several yards away, has been shown to create puddles of said liquid when upgraded, relatively rapid fire, large ammo capacity.
Mag-net Launcher - weapon slightly smaller than an RPG, moderate weight, fires large (about 6' by 6' possibly) nets of electric energy that wraps around a foe shocking htem with electricity constantly until it dissipates after multiple seconds, giving Ratchet time to pull out another weapon and attack, slow firing rate, noticable reload time, small amount of ammo.
Negotiator - Rocket Launcher slightly larger than a machine gun, lightweight, has very slight seeking properties and large explosive power, relatively fast firing rate, moderate reload time, holds about 10 rockets.
Pyro Blaster - Relatively standard flamethrower, has about 40 seconds of constant use before running out of fuel, has slightly fanned out spread of flames.
Shard Reaper - Shotgun which fires shards of sharp, tough material at high velocity, moderate firing rate and ammo amount, shards contain "Pyrocidic nano clusters" that cause shards to explode with small force shortly afiter hitting something and liquid nitrogen which can possibly freeze parts of the body it hits.
Shock Ravager - one-handed weapon the size of the wrench at first, but is really a whip of electricity up to 5-6' long, having 30 energy cells, which means 30 "cracks of the whip", specifically designed to grasp and remove/destroy enemy shields.
Fusion Grenades - Glove-like device that holstered a moderately-powered launcher for grenades, firing them severla feet in front of Ratchet, exploding 1 second after being fired, holds 8 grenades with large explosive power.
CryoMine Glove - similar glove-like device invented by Ratchet's father, creates mines that tracked teh foe and rolled to them, exploding with a large amount of a freezing substance (most likely liquid nitrogen), holds 8 mines.
Mr. Zurkon - portable assistants that are durable and powerful, shooting powerfu lazers at foes by itself and being aggressive, Ratchet can hold roughly 3-5 with him, spits funny and distracting one-liners in the third person ("You are not fit to fight Mr. Zurkon."), when defeated or used up, simply self-destructs in a very minimal explosion.
RYNO (Rip You a New One) V - There's a good reason this thing is banned throughout the galaxy. This huge, heavy minigun-like weapon fires huge amounts of rockets with moderate seeking and small explosive abilities at moderate range, while also firing nonseeking larger rockets with huge explosive power at moderate distances, being entirely automatic rapidfire, shooting huge amounts of rockets at one time, has 1500 individual rockets and a small amount of large rockets, firing one large rocket every six seconds of continuous fire, very heavy, moderately quick reload time.
Plasma Striker - Lazer Crossbow with moderately powerful scope (about 50 or so feet can get a nice closeup view), has nice power, is heavy and large with good kickback, pinpoints weakpoints on foe with circles, holds little ammo and has slow firing rate, relatively impractical at close range.
Tesla Spikes - a group of posts inside a glove device, holds 6, generates an electric field that effects anything within the area of the posts, but the posts must stay within about 10 feet of each other, and it only effects foes on the ground.
Hoverboots - Ratchet has shown prowess with hoverboots, doing walljumps, jumps, highspeed courses, fast turns, etc, while still being able to attack with his wrench/some weaponry, keep him hovering a good foot (give or take 1-4 inches) off the ground.
Clank
Fists - Clank can attack with his fists in both slapping and chopping fashions to moderate effect, able to damage some wild animals.
Jetpack/Helipack/underwater capabilities - Clank can propel himself (and Ratchet if on his back) up into the air several feet and can use a propeller in his head to glide slowly in whatever direction safely to the ground, and he can be used to propel himself and Ratchet underwater.
Tie-a-rang - Clank has had a Bow Tie outfitted with razor blades and given the ability to return to its thrower after flying a few feet, dealing good damage, with Clank clipping it to his person because of hte magnet on it.
Cufflink bombs - Clank also wears cufflinks that he can remove and detonate to moderate explosive effect, and he presumably holds a small amount of extras with him.
Storage/Shrinking - Clank is essentially Ratchet's hammerspace as well, having a device inside his chassis that apparently shrinks weaponry and stores them, allowing Ratchet to quickly and easily access and carry his large arsenal of weaponry.
Thats it. Whew. Feel free to not use any of those, but hose are the most plausible weapons in the Future series (at least to me) for IRL fighting. link to this post in the OP if these are added for convenience (and for me to be important) plz.