See if you can find some used stock focus rims, that may be the cheapest , also I would consider 16” rims. 16” tires tend to be less expensive.
My rides a 2002 SVT track car, & Boosted 2007 ST with the SAP.
The helmet has a special meaning for many drivers. How important is it to you? - It protects my head.
Do you have any special rituals when the helmet is concerned like many have? - I wipe it so that I can see better.