Depending on you co-ax, the answer is 99% no.
Usually the esc's and receiver are built into a single control board, so you'd have to isolate the brushed ones and find a way of making the signal get to the new ones.
TBH I wouldn't even bother with anything co-ax. I have a pretty big one and it flies like a big stinking pile of crap compared to even a basic 4 channel with flybar (and will not handle even a mild breeze).
My advice? buy one of these (if you want a copter) to get you hooked:
http://www.banggood.com/WLtoys-V912-...e-p-75662.html
or one of these for a starter quad:
http://www.banggood.com/WLtoys-V222-...r-p-75386.html
BTW this is a control board similar to what I assume is in your co-ax
That is the one that's in my 912 - built in receiver, and 2 esc's