Hayden Lynn
Do a google or yahoo search on Hayden Lynn Las Vegas and you'll find her site. You'll also find reviews of her on the TER site, she tends to always score 8 to 10 (out of 10) for looks, service and overall rating.
I've seen her a few times, and wow, she provides an incredible GFE, bbbj, msog experience. Well worth it, I generally consider her the best SP I've ever seen.
Her rate is relatively high at $500US for an hour (but she isn't a clock watcher since every time I've seen her, she stayed for over an hour), but this is a typical rate for a quality SP in Vegas.
The high end in Vegas is easily in the $800 to $1500+ per hour, and I think Hayden Lynn is probably as good as the SPs at these higher rates.
Other tips: the Eros Las Vegas site will have some gems on there but unfortunately some rip-offs as well, I'd advise the TER site for filtering out quality SPs.
There are SPs walking along the strip and inside hotel lounges/casinos at night, but I find that these SPs tend to be of low quality and/or mileage.
If you check out Hayden Lynn's site and if you are interested, contact me for additional information. The unfortunate thing about her is that she is usually late for the appointment.
Another tip for you, the hotel you are staying at can make a difference for meeting an SP. So I highly recommend that you stay at a hotel that has a ton of hot looking women walking around during the evening, so when the SP walks through the hotel, she isn't really attracting that much attention since there are already hundreds of hot women around.