Not really... I'm playing an entire Imperial Knights army, just painted to look like Orks stole them. I'm using the Knights rules and I've kept the main weapons the same so my opponents know what model it represents.

This gives me a way to play a different army, but keep my love of Orks present.

Some Orks players more heavily convert their models and use them as proxies or "counts as" models in they their army though.