few suggestions. feel free to tell me to shutup
if you cant identify the carb easily, finding parts could be tricky. guessing and hoping isnt always the answer. then again, a quick trek to a marine mechanic could sort that out.
manifold. no real issues except clearance. frame, clutch cable, that sort of stuff.
cant really tell, but is it a diaphgram, or bowl? (ie, gravity fed) integral pump, or separate? fitting a pulse line is easy, but beware some carbs DO require a return line. extra plumbing to worry about. some require a fuel pump, or at least a pressure tap on the crank case.
the most annoying part on fitting alternate carbs, in my mind, is cables. either it takes forever or its a five minute bodge job with some bent steel strap... oh, and air filters. if its a neat self contained affair, great, if you have to fab one up.... have fun checking out things like pvc pipe and lawnmower filters
worked on my old ct110 at any rate
alloy plates and a small "donut" car filter? micro cyclonic filter free? oil bath? etc etc... imagination helps
personally, if i found a nice cheap source of them...the walbro rotary barrel type carbs. WJ series? iunno. they just have the cable fitting fitted as standard. as do the old school slide types. hard to find them now!