i just ordered the 11kv4 from elemental designs, one of our sponsors. the mounting depth is slightly shorter than the 10ib4 which means you don't have to worry about it hitting the gas tank, but you'll probabaly still need some type of spacer.
the 11kv4 was $115 shipped, and it comes with a three year warranty (something you don't get trying to search for a used JL 10ib4). i went the route almost every CL member recommended with the JL and got a dud.
i don't know how it's going to run on the stock amp though, or if it's even possible.