Buy it from a reputable place, and make sure to get a "US" version or you'll be on your own when it comes to service - Nikon won't touch grey market stuff. Should cost abou $1k for the body alone. Some stores might have a grey market version for a little less money but on a DSLR I wouldn't risk it personally.

I don't have experience with those lenses but you might check the reviews here. There are a lot of good 3rd party lenses, I've got a Tokina that I've made some big prints with and they look great. And yes, you can immediately delete a shot (but since it's hard to tell from the small LCD monitor I wouldn't do it unless you're sure).