well, my recommendation for quality/cost best deal would be hobbywing stuff, which you can get on hobbypartz.com .
I thought your question though, was whether the esc that you own could run brushless motors. like I said, some can, but many cant. If your "friend" is going to buy a new esc, he/she should consider just running brushless motors too, since they're easier on batteries. If he really just needs a brushed esc, I've got a tekin rebel 2 for sale he can buy for $25.