Maybe try
https://rchobbies.com.au/store/ as i know they stock Team C which is the same kit as a Madrat/Xpro. If they dont have what you need, they will definitely give you good advice.
You need to find out what turn your motor is and then you can find a cheap brushed esc on ebay these days. Im running brushed in my B4 and i have a LRP Quantum Super Sport and its handling my 11x3 motor fine. As brushless has become the rage everyone is getting rid of their brushed speedos so a good deal can be had on some quality gear. Id stick to the main brands like Tekin, Novak, LRP etc.
My 2c.
Alex