I'm a big fan of creekers, personally. The Diesel will do exactly what you want it to, but you won't find one for cheap. You can, however, find some pretty good deals on a CFS. While it's not exactly a river runner (quite the opposite), I find it does run rivers pretty well. And, it creeks like a dream. It'll surf, too, and spin if you know how to.
The only issue with these kinds of boats for surfing is their length. If you're going to buy new, and want a boat strictly for creeking but want it short for some surf then I would buy a Bliss-Stick Scud. Those boats are wicked fun in a play hole, even though their abilities are limited.
Sounds like the Diesel might be the ticket, though.