BL E-zilla , BK 7020/9L possible?

Hello,

I own an HB E-zilla and I want to go brushless...

It is stock with 13cm diameter tires, 66T spur and 20T pinion (1/8 shaft), weights 4.3 kg.

Will work this set-up?: BK 7020 (only 70 Amps) and a Feigao 9L.

The batteries are LRP 3.000mA 6 Paks and LRP 3.300mA 7 cells packs.

I have a motor heatsink/fan . Should I install a ESC fan, too?

regards.