Need advice on finding engine parts and what to look for?

I just bought a 75 Duster with no motor or trans. It originally had a 318 in it with an AT Trans. I want to put in a 360 with an 833 4spd trans manual. Where do I start finding parts? I'm having trouble locating parts and I don't know what donor cars to look for that will fit what I'm looking for. Does anyone know where I can find the pedals and what cars will fit? I heard I can use a 360 truck motor, but not sure what years would fit where I wouldn't have to mess with the fuel injection. Would a 5 spd out of a Dakota fit and would I just have to cut out the center hole for the shifter or would I have to cut out the tunnel? Would a newer trans work? It's hard to find a rwd with a 4 or 5 spd. I wouldn't mind putting in a slave drive and use a Wilwood clutch assembly, if that would work. Any help would be much appreciated!