If you Raid0 the two 7200.10's it'd be pretty close performance-wise, however raid is a little less reliable. Raptors cost more though, so it's up to you how much you want to spend.
Your getting a LOT more space for about the same performance. Your getting 720GB opposed to 150GB for cheaper...as stated they aren't as fullproof as a solo Raptor but I doubt anything will go wrong. Go with it man