6 wheel robot

for the motor:
i am thinking brushed motor but im not sure about the speed/torque of them
for the wheels should i have all 6 motorized or just the last 4 and have the 2 front ones only to turn

Battery:
instead of using a battery that you would find in an rc car i was thinking of using a power bank for its large capacity but i dont know if that wold work

Controller:
i want this to be radio controlled but all the good ones are extremely expensive what are some of the lower budget, quality controllers,

It’s entirely your choice actually. Normally six motors will cost more than two.

Would having 1 motor for the 4 back wheels and 1 for the front 2 be better

Honestly, not sure.