Well as I'm on the heavy side too (really heavy that is.. being 6'8" doesn't help) I'll let you know how the Mono6ti perform in case they're worth the hassle of finding a pair, used or new.

The most common are Avid Juicy 7 they're the Volkswagen of bike brakes they just do what they're meant to do with no fuss or reliability problems. But after all it always depends on the final usage and also I'd say your weight. If you weight more than the average rider like me you'll need something with more power but also something that is more fade resistant otherwise your brakes will catch fire or melt. (well not really but you get the idea) Before I forget.. the budget that's quite important too. :P

True that, it's been in my room since august '09 (when I bought it) and because of one thing or another I haven't been able to ride it since except for one time but it had a flat on the rear, the saddle was wrong for me and the rear shock was too soft.. lol. Btw I'd suggest you buy a brake that is still in production, yes you can still find pads and spares but the brake itself it's reeeeeally hard to find in a decent condition and at a decent price. ;)

You're still using that frame?

The highrollers are probably too close to your current tires, best thing to do is go for extremes, like when setting the suspensions, then after you see which extreme you like more you start refining. It usually works, sure works for me. XD

Minions should be grippier but should roll less easily, not that it would make a huge difference. Depends on where you ride to, which kind of terrain etc.

Your bike is lovely man! Nice colors and nice helmet too! How does it rides?

I hope Manitou still makes spares (probably they do) otherwise I might just go for it and make a CNCd custom adapter.

They feel really nice, and they seem to be as stiff as I needed them! The only problem is the brake adapter, apparently the Avid brakes don't fit so I need to find another adapter but it's no biggie. ;)