does anybody on here know what the differences are between 3dr runnig gear and 2wd saff running gear or is it a straight swap over

i am going to start a 3dr build and am wondering whether to just buy 2wd saff running gear or original 3dr running gear

i am talking about front xmembers aswell as rear end

also does the 3dr have power strg??or just rack and pinion and is the abs system the same on both cars

sorry for all the questions but i guessed you lot would be the best to ask

pugo