I don't live in Edmonton, but last year I frequent the city very often. I cannot comment on MPs because I have never tried them. For many reasons, including $, I would avoid the established SPs... these are the ones that seemed to be advertised everywhere, at least that's my impression when I checked the local papers and phone directories. The new ones are better and younger, but they are usually not listed. I got in touch with two through another SP. The best approach is to politely e-mail the SPs or agencies and take it from there. Ask for photos so that you won't be surprised. Also, if you find one that you like, try to see her for more than an hour because the fee decreases significantly.
I will be back in Edmonton later this month. If time permits, I will try to get some fun, but first I must do research...
Have fun on your visit.