Lots of options in Vegas....
I concur with all the warnings to avoid the guys handing out all cards, waste of time, money and maybe your safety.
I had luck finding a girl on CL and did plenty of research there along with other vegas sites. They overlap tons even from the highest class sites right over to CL, you can cross reference if you do enough research. HOWEVER, the problem with using websites is your possible lack of access to the internet while there.
SO YOUR other option is as pointed out above, most casinos will have amateur pros walking around without hesitation as of midnight. The Venetian, Hardrock Casino and The Palms to name a few.
Just go to the Venetian and play some blackjack, you will be solicited in no time. And not in a bad way, plenty of wholesome, well dressed, sociable women to talk to. I met a couple women sitting at the bar at the Hardrock Casino that were beautiful, great to talk to and got their number from. Didn't follow up though. Rates are very reasonable ranging from $250 to $400 per hour. As mentioned above too, you have best of both worlds spending some time with them, having a drink before you have to decide.
Personally I found a "lady" or courtesan, entertainer, whatever the title at the Penthouse Club. Now at first they come across as more exotic dancers as their limit but after some fun getting lap dances at exhorbitant prices I met a gem of a beauty at the bar. Totally unsuspecting I fell in love with her, sorry in lust, instantly. We negotiated price and went our separate ways to meet back at her hotel casino for a drink and then the whole evening.
WARNING: I would not recommend this practice going it alone as I broke away from my buddies. I was okay but I've heard stories.
WARNING #2: If you do call one to your hotel, be vigilant when she arrives and watch the door. They have all kinds of scams going on leaving it ajar only to have someone walk in later. Off duty cop at the sports bar filled me in on the whole thing; everyday he says there are stories of guys getting duped. Hell you can get duped in Edmonton on CL; Vegsa is the big leagues, so the dupe can be bigger too.
Cost me a small fortune at $1200 BUT THAT WAS FOR THE WHOLE EVENING. Midnight to 10 am, no holds barred, anything goes! But keep in mind we hit off immediately and had a huge connection.
She is a former playmate posing many times for Hugh Hefner!
One of those great memories I will cherish when I'm 80.
And I still keep in touch with her.