I think I'm very with you on this part - I also have a plethora of campaign ideas; I don't think a single use system would keep me happy (and hasn't, to date). Coversely, like you, I want to not have to make up too much stuff myself; it's REALLY awesome in GURPS that a lot of stuff is premade in the other supplement books (like, I just used a lot of stuff for my upcoming SotB game from the GURPS Space pdf I got some years ago (why is it so hard to find a decently priced print copy? Why don't they do it like they did for other books with Amazon's POD service? Gah!).The advantage of a crunchy system is toys to play with, the advantage of a tool-kit game is being able to use those toys with a wide range of campaign ideas.