I would recommend that you choose the braking system that you think will provide you the most performance for the budget you have available--
FOR THE FRONT!
Don't worry about the rear yet. The front brakes do about 80% or more of the work on the track so that's where the real upgrade is. Pick the best front kit for your needs and worry about the rears later.
The front is where the big gains are. Sure, upgrading the rear will help a little, but the bang for the buck ratio is much smaller. Whatever front system you choose shouldn't dictate what rear upgrade you do. Willwood makes a fairly nice cheap rear kit that should be more than the rear will ever need.
Of course if you have the money, the rear Porsche kit would sure be nice. But I don't think it is really an improvement that justifies the cost if you're on a tight budget. But it would be nice if you're looking for a matched set....
I can't remember all the specifics of the Alcon 6-pot set-up, but I think it's safe to say they would be "more than adequate" for about anything you could throw at them.
Anyway, the fit of my Mov'it kit--the parts themselves--was beautiful. Like the inner workings of a Rolex.
The installation is probably no different from any other big brake kit out there. Cutting the ears off the spindles, etc....
But like with any big mod I do to my car, there were a few "issues" upon installation.
There was a ridge of material on my driver's side LCA that would contact the rotor. Had to grind that smoothe. Funny, the passenger side LCA was already ground smoothe from the factory. There's GM quality for you....
And the new studs that Mov'it supplied didn't seem to fit very tightly in the hubs. They worked OK, they just weren't as tight as I would have liked. I used new hubs that are a different design than the old ones so for all I know they would have fit fine in the old ones just fine. Who knows. $20 at Summit for new ARP studs fixed that. No big deal.
Track performance goes without saying. On the street you'll notice a much firmer pedal and better braking feel overall. The modulation is much easier, much less of an "on-off switch" that the stock brakes are in comparison.
I got the kit from Steve D. here:
http://www.ultimategarage.com/bigbrake1.html
The biggest problem with the Mov'it kit right now is availability of the calipers. They seem to be in high demand these days.... Expect a wait when you order. If you have a specific timeframe in mind that you need them by, give Steve D. a call and he'll tell you if he can get a set to you by then or not.
Hope that helps.
------------------
96 Z28 M6
13.59 @ 102.96
MODS