new engine options: used / collect parts

The final entry of the multi-part posting. This time its about helping me make a decision on Hapy's stock 1700 engine. The choices are below, and this post is for the last 2: used engine or collect parts. I'll have one post for each choice, so they don't get too long. Hopefully, I'll get some good feedback and be able to make a good choice.

1) keep the limper
2) a Raby Camper Special
3) the TDI engine I have on my garage floor
4) a BusDepot special
5) some used engine off of craigslist
6) build one from parts collected off the 'net, parts stores, etc

The final 2 choices aren't really viable, but I'm adding them as alternatives anyway.

5) buy a used engine off of craigslist or wherever.
This is dicey. Obviously, the person selling it has their reasons. Maybe they're just killing a project. Maybe they're selling a dud. Assuming there's a good compression test to go on, a decent engine could be found this way. This doesn't get me any closer to where I want to be, though: more powerful, better known engine. Actually, the best I could hope for is slightly better power, but a lesser known engine. Which is better? *shrug* They can be found for $500, though. That's pretty cheap. And no shipping, but you gotta be fast, know what you're looking at, have a way of getting it home, and cash in pocket. You have to be willing to drive to the very edges of town as, inevitably, that's where the current owner of your engine lives.

Choice summary ranking as compared to other choices (1st, 2nd, etc):
cost (1-6): 2nd
work (1-6): 3rd
power (1-6): 5th
mpg (1-6): 4th
reliable (1-6): 5th

6) buy parts and assemble it myself.
This has the bad side of having to assemble it (Raby) without the power boost, reliability and general well-being found in getting a full kit. For some reason, no other manufacturer has gotten into the space of complete rebuild kits. You can get piston/cylinder (P&C) sets, camshaft and lifter sets, and gasket sets, but there's no complete set. So, you're wading through the shiny magazines trying to figure out what won't blow up if you put them together. There's your recipe for a restful vacation - put one of those mystery combo's in your bus and head for the outback. Uh... no. The pricing probably lands below the AVP, but with assembly. MPG is really anyone's guess... just like the engine :)

Choice summary ranking as compared to other choices (1st, 2nd, etc):
cost (1-6): 3rd
work (1-6): 5th
power (1-6): 4th
mpg (1-6): 5th
reliable (1-6): 6th