Unfortunately, there is no single site that is 100% reliable as far as finding SPs is concerned. The best thing is to use AW to find a girl who offers the services you want at a price that is acceptable to you - once you've done that, use the search on here to find reviews from guys who have actually seen her. I'd also say that "gut instinct" plays a large part in the selection process, if, after checking her profile and/or reviews something doesn't 'feel' right, don't do it - you'll save yourself money and the regret of a bad punt.