B customs (Better off sticking with chomp in my opinion)
Inhaling bite - Sucks opponents in; does less damage. I haven't tried this one out,
Garlic breath - Long delay, but when the breath comes out, it stuns (trips and knocks back people who are too far away). Not very useful in my opinion as chomp has a lot of utility
Side B customs (Matchup dependent)
Speeding bike - Less hp (breaks from one bounce) but faster and has insane knockback. Likely Wario's best custom as Rakurai has said, it also combos into waft at some percents!
Burying bike - More hp (I think it even bounces more from some throws) while burying opponents if it runs over them (even if Wario isn't riding the bike). Has a lot of potential for bike throwing combo strings and abusing grounded opponents (although Wario has no uplifting attacks that i know of as opposed to Sonic's up-smash)
Up B customs (Personal preference)
Widescrew - Much larger directional choice (can almost go horizontally), however it loses some height
Corkscrew leap - More height and faster vertically, however it can only go vertical, so it is risky as you could get knocked off your bike
Down B customs (Personal preference: Power - Standard waft, Range - Rose scented, Speed - Quick waft)
Rose scented waft - Less knockback, 10 second faster timer, MUCH larger hitbox, does damage over time from a sapling. I love this custom move
Quick waft - A faster waft. Fully charged it comes out slightly quicker than an ordinary waft, however it won't kill nearly as quickly. Very useful if you're worried about missing a waft
Personally I like 1212, none of Wario's custom moves are too inferior from each other (other than maybe his chomp customs), and he gains a lot from speeding bike and rose scented waft in some match ups as he can cripple recovery with their respective speed and range