Need advice on 5 cell speed control

I'am to convert a Revo into brushless, and i've a MM speed comtrol, but i want to run my revo on 5 cells li-po, with a Feigao 9XL motor.
I'am not sure to take the chance to put 5 cells on my MM controler, so could you tell me wich speed control to choose.
I've look at the Quark 125 but don't know if it's a good choice. Some one ever tell me that this controler have bad habit to overheat.
And i'am not certain if i want speed over $400.00CAD on a MGM.
Need help please.

Thank you!

David