The Nosram and LRP ESC's don't need a fan even with fairly hot motors, I've run a 4.5 in my 2wd fanless and had no heat issues (just grip issues
).
I tried a Nosram 7.5 with the 12.5mm rotor at Kidderminster and
really liked it. It was fast enough without being silly, created no heat, tires lasted ages and I was using around 800-900mAh per run
