Yes, we still live in Anchorage. We did not put our daughter in daycare as a baby/toddler. I was fortunate enough to be able to stay home with her (and our older children) at that time.
I would suggest looking for a daycare provider that has been licensed. I'm thinking that a small in-home daycare provider would be better than a large daycare, but I don't know–never having done this.
The biggest thing would be to find someone who can understand what PKU is (generally), and the importance of following the diet strictly. It would be good also to find someone who can be matter-of-fact about the diet, not too sympathetic. As your son gets older, it helps to just talk about Yes and No foods. I think he'll grasp what he can and can't eat much more quickly than you'd think.