I'll state a few - Zippy, Rhino for cheapness, Neu, Thunder power, hyperion, poly-rc, polyquest, Enerland, Flightpower, Trakpower,,,, Elite,,,, True Rc,,,,, Not Maxamps
Since it's a buggy with a low KV motor, some 6S ~3000 25C+ lipos would probably be your best bet. I believe zippy have some at that spec, or neuenergy has 6S 3200 30C cells. The neu packs would be my choice.
I'll state a few - Zippy, Rhino for cheapness, Neu, Thunder power, hyperion, poly-rc, polyquest, Enerland, Flightpower, Trakpower,,,, Elite,,,, True Rc,,,,, Not Maxamps