like that you don't need mechanical breaks. afaik the tekno conversion kit for example is designed for a setup with mechanical breaks.
At the moment I have this esc, until I get the car esc replaced:
http://cgi.ebay.de/ioi-Brushless-Reg...item3350cc440c
for 75 usd incl. bec quite ok. despite some say that plane esc's are no option, I'm quite happy with them. actually, I wished the car ESCs have the same reliability...
There are various esc's like that out there (e.g. mystery), and I think they don't all have the same quality.
you can get the mount done by yourself for sure, to keep the budget low (and then spend the money on a good motor and batteries).
when using a car esc, you have various throttle curves, drag breaks etc. so both sides have their benefits. some would say, on the race-track only with a good car esc, as some say, with mechanical breaks you have the advantage of drifting in curves...
flo
edit:
when going for the ezrun, u should go for the 150a/6s version, 4s in that truck might not be sufficient