For nightblades in general Khajiits can succeed as magicka or stamina builds as their racial passives are geared towards increasing critical, combat health regen (which is useful for anyone), and stealth. They won't be as powerful of casters as say Bretons, and for a bow (which would most likely be part of a stamina build, but not exclusively) Bosmers are the way to go for most people, but you can still be very successful in any build for the most part. And if vampire is your flavor, they make really cool looking vamps as well. If your really not sure where you want to end up when you first roll, this ones vote would be go for Khajiit