Engine swap part replacments...

hey everyone, im just wondering, i wanted to get a J-spec engine into my car... however i already gotten an air intake. its not really a big deal, but i was just wondering if i would have to replace that... or is it specific to the engine? if it is im planning to get a Kl-Ze for my Mx-3. i know i have to get new mounts (at least i think i know...) but what else would i have to replace?
also, how much would that cost? ive got 4000(cdn) saved up.

thanx for any/all help

Damious