With the 7th pick, I think you'll have to be very flexible this year. I've already seen drafts with Kurt Warner still available at that pick, and the order in which the second tier of RBs is being taken varies greatly from draft to draft. At #7, even picking up a top WR isn't out of the question either, although I'd personally rather have a QB or an RB.
In general, though, with that draft choice I'd lean toward grabbing a solid RB - the QBs will still be there when your second-round pick rolls around.
As to sleepers, we'll be putting up a few new names very shortly... At the upper level, I feel that Antonio Freeman may be undervalued in many drafts; near the end of deep drafts, D'Wayne Bates is looking good right now...
And Q-Tip - that has to be the best etymology of the word "sleeper" that I've ever heard! (not to mention some good sleepers!)