The closest thing to Marth is of course, going to be Marth.
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He's got some nice buffs since last patch, and doesn't quite play like Melee due to physics, but since you don't wanna main him... Lucina maybe?
What you seem to like is long ranged spacing, since Melee Marth is all about that. Characters that come close to such playstyle in my opinion are
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and
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, but
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might also be your cup of tea since he plays the 'wait and bait' game similary to Marth.
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is very straight forward and is all about applying his max range to outrange his opponents. He can also kill real early, like Marth can with his tipper. So that's a thing that's easily carried over. All you gotta do is adapt to a slower and steadier playstyle. He's got a great F Air though, that's quite

like.
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is really adaptive compared to Ike. Don't know too much about him though. Same with
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.