be careful, all 20A ESC's are not the same. the 20A BLHeli has a 3A BEC, those others have a 2A. so if you are planning on running multiple servos, plus your Rx, you better be careful. brownout i believe is the word. myself, i will spend the money on the BLHeli and do the work to solder knowing that i am getting a solid product.
programming cards can be found here......
Emax ESC Programming card
laters,
me