Actually you could probably use 1:24 Plastic Model rims just as easily, there isn't a large difference.
Three possible sources:
www.jadatoys.com
www.hoppinhydros.com
www.collectablediecast.com
Jada makes a variety of cars close to 1:24 which I routinely rob for their wheels. I hope you like chrome.
Hoppin Hydros has some wire rims for the discerning 1:24 owner. I hope you like wires.
Collectable Diecast offers some Dub City knockoff rims. Also chrome. Just search around on their site.
As for attaching them, check out the tutorial section or use the search feature, somebody might've shared your question. If all else fails, rob another car of the same brand or something cheap.