So I measured the radius of drive motor axle to floor, and it's about roughly 5 and 1/2 to 6 cm off the floor, which means best bet for wheels is possibly a 120mm-125mm wheel maybe? And seeming as that's the case, would this be a suitable wheel to go for here?

If not, what are some other suitable wheels at that size, considering that I don't have a lot of space to work with, and I'm wishing to make it a direct drive from axle to wheel.