I think anything in the style that fits over the nubs would work. I think they're 10 1/4" or something like that. I haven't really shopped around for options since I had my current setup in mind.
I'm not running caps, but have spider rings that fit over the nubs just like a hubcap, in addition to trim rings, bullet caps, and lug nuts.
https://media.fotki.com/2v2aUsTpbxDubp.jpg
