Uprights and hubs will be designed from scratch - CAD software will play major role
tyre cost is not a problem, plus single seater will see only track surface. Regards brakes it is a bit of a problem, because the majority of brakes are designed for vehicles above 200-250 kg, and motorcycle calipers won't be any good - they use huge brake rotors. So the only way to go is to design custom calipers. What are the bad points of smaller wheel instead of bigger one? not counting reduced length of pneumatic trail.