Well, Yuen Lui is the old standby and the big one around here. We actually know the Lui's and it is a nice familiy owned business. For the more personal touch, we've used a couple of folks, but the main way we've found them is actually through school auctions.
A smart strategy is to do some giveaways with a parents. Most folks don't have a friends to friends recommendations. I've not really understood why since photos are so personal.
Your portfolio looks great btw!