I think the main differences are the skill level of the rider.
The Evo is a beginner kite, more forgiving and easier to handle. The Rebel is a general all rounder, good in most aspects, targeted at free riders. The Rhino is the high performance kite, very powerful, big lift and hang time, not very forgiving.
Then you have the Vegas, a kite designed for freestyle riders that prefer C kites.
From what you say I'd go for the Rebel....but if you want to get into unhooked stuff maybe look at the Vegas, it probably has nearly as much depower as the Rebel but will be better unhooked. I'd stay away from the Rhino if you are looking at going unhooked, I reckon it will be to powerful and may limit you/make it harder to learn unhooked......but I stand to be corected as I have never actually flown any of these kites, only know people who have