That's a great choice of first bike but its unlikely you're going to get your hands on a 2008, probably going to be a 2009 at this point, MSRP $3999. All orders for the 2008 250's that haven't been shipped yet were canceled.
I put a deposit on one in late June and sat around and twiddled my thumbs only to hear that it wasn't going to happen and that I could get on the waiting list for an '09.
Here's a bit more information:
2009 Ninja 250R - What to Expect | Kawasaki Ninja 250R Parts, Reviews, Mods, and Information