Aaron,
I have a white doughnut peach as well, "sweet cap", the peaches are fantastic. The crops in Colorado are a hit and miss do to late frosts, but the good years are amazing and worth the wait.
If you did not know, all of the reading I've done on peach/nectarine seedlings, they are the only stone fruit seedlings that almost always produce a good quality fruit. For that reason, I'm letting my seedling grow out to see what I have before over grafting them if they are only so so.
Ask Phil, he said he only has a little Scionwood available for the Flat and wonderful, he might have some left.
I would be more then happy to send you some Scionwood of my sweet cap if you like, just shoot me an address.
Scott