I have 15 inch TKOs and love them. If I was going to go Level 8, I'd go with the ZX to get the scratch guard. I'm considering upgrading to 35‘s and if I change wheel size, I'm debating between ZX and the rugged ridge with guards.
One note to consider. I understand doing your mods piecemeal, but I would be nervous picking a wheel without knowing what tires I'd be using for awhile. If you just change wheels to the same size, when going to upgrade tires, you may have limited yourself to a small set of tires available in that wheel set. So if you do it, be sure you like the tires available. I think I remember that tires for 15’s are cheaper than 16s, and 16’s cheaper than 17's, 17’s cheaper than 18’s, etc. generally speaking.