I'm with jhautz on his suggestions. The gearing is where you need to be focussed as well as how that will be impacted by your KV. KV doesn't equal speed unless it's geared that way. And if it is - you'll be burning more amps at that speed than with a lower KV motor geared to the same speed. If you want run times, then a lower KV is best.
If I were you, I would get the 1515 in the 1900KV for full flexability. Besides, I have a link here for you where they're selling one for under $200 - new. This is what I would get if I were you:
http://www.flydma.com/catalog/produc...roducts_id=245
Any of those motors will do about what you want with the right gearing so I say why not save the $$?