Wheel Works originally refused to replace my run flats. I ordered Avon Tech M500's from Tire Rack and had them sent to Skipps in the Bay Area (I'm in San Jose). They fitted them no problem, and pretty cheaply too.
Interestingly, now I already have non-run flats that now are due for replacements, Wheel Works will now fit them.
I highly recommend getting out of the run flats - you'll think you've got a new car!!!