check out pirate 4x4, chevy thunder drive by wire, ls1tech, lt1swap.com, nook and tranny lsx info, gmefi.com for a bunch of info on the ls series engines. good stuff for a read-thru before spending money. don't worry about the car end of things, if you have the engine and trans etc it will fit into lots of different vehicles if you decide the old iron is too heavy or for whatever reason. a guy i work with put a 5.3 truck engine in his mustang and then threw a turbo on it and it worked out fine. you will have no problems if you have a few fab skills. I would recomend an overdrive with whatever engine you use. there is a reason most newer vehicles come with 5 gears or more, less rpm spread between gears, so you're not wringing the engine out like a wet rag before shifting, plus a good overdrive for mileage. also, there is always somebody looking for ls engine swap stuff if you get into it and then change your mind.
there is a guy on the ls1tech that has pics in the forums. it's a corvette engine in a '76 I think.