After reading what Quadzilla and others have said when I eventually add propane to my truck I plan on getting the Powershot 2000. Propane is one thing, IMO, that is simply not worth doing yourself. There is too much room for failure and damage unless you really understand propane injection.
As Quadzilla said:
Propane doesn't destroy engines, people destroy engines.
I would imagine that this applies to a lot of do-it-yourself systems that are installed without understanding the possible problems with propane injection design.