As far as buying a Hemi, yes E-Bay would be a good start, but most engines your going to find are stock with no rebuild which means you'll have to sink some money into it unless you want a stock motor. As far as trannys the 727 will work but your going to have to get another bell housing and probably shorten your driveshaft. If you want to pro street or just hot rod it thats up to you. Either way its alot of fun and alot of work, but the finished product is what its all about.