I have tried various modern brushless systems in a Cat'98 (ie Cat 2000 drivetrain). The Ezrun 5.5t did kill the back belt very quickly, but an Lrp 7.5t worked really well. It can take brushless, though perhaps not the very hottest winds. The 9T Ezrun seemed to work best though - as its a slightly smaller motor it has less torque, but still high revs. Means it goes fast without dumping too much power through the belts.
Actually this setup:
Motor and
ESC is a great brushless starting point. Its not BRCA legal so not permitted for regionals, but fine for club use. Lots of people use them as they are cheap but robust and effective. That ESC is the higher spec version, so can take a faster motor later if you want.