I recently replaced my rotors and entertained the idea of drilled/slotted product. One of the better product I found was through "stainlesssteelbrakes" :

http://www.ssbrakes.com/

They claim the problem of cracking is reduced through their manufacturing process. I ended up going with OEM product, mostly because of the price.

Occasional use of brake cleaner (especially after wheeling) really helps with squeaking pads/rotors when you don't have hose handy to rinse them down.
Good Luck

'02 Montero: OME suspension, ARB front bumper, homemade skid plates & spare tire Blitz can mount, extended diff. breather, K&N air filter, Optima Yellow Top, BajaRack, IPF lights, Goodyear Duratrac 265/75/16's, RUD 4x4 Grip chains