does anybody know if a JDM h23a will fit into a 2002 Civic EX... if not any suggestions on what would be the best way to go for engine swap?

It's do-able but not easily. H23a's weigh more than your typical B16 or B18 engine swaps, so that's something to consider also.

they are also not straight drops either, a few modification will be made in order for the motor to fit and sit correctly. dont waste the money, unless you plan to keep this car as a track only monster, get yourself a b16/18/20 they all are good swaps.

You could put a H23 in but its not recommended seeing how it takes more money to do so you should save yourself the time and just purchase a B16, B18, or B20 unless its a track monster.
Check out the full engine swap kits here. http://www.totaljdm.com/?id=40320