My husband and I used Already Adorable two years ago. As PP said, I think they are the only place in town - but there are a few other options if you are willing to drive up to Phoenix.
The experience was amazing. I still look at my 3d sonogram photos. One of the first things I declared after my son was born was how he looked like his 3d sonogram. They often have specials - if you go to their website you can sign up for their newletters.