I've got a 26" chameleon up for sale shortly, it's got an EBB to manage the SS'ing and is disk compatible. I've been running it as a SS XC bike for a few years, so already built up with a Hope SS rear hub.
The only thing is it's a size L, so unless you're tall it might be too big to chuck around a small track - would work for me but I'm 6'3"...
Let me know if you're interested and I'll send some pictures, I've not thought about price yet but would be within your budget.