Perfect Clones (TD on other forum) lists an IWC 3717 with a Swiss 7750 that I've had my eye on for bit over $800. There maybe other Swiss chrono models as well on there. I've thought about pulling the trigger, but I can't help but be leery, especially for that kind of money.
As gtanak says, might be better to buy the Swiss movement separately from a reputable source and swap it in.