This might sound maybe harsher than I mean it to, but what the hell. I think you're setting yourself up for failure.
Most non-working girls in Vegas travel in packs. If you see a pretty girl hanging out at a bar by herself, odds are she's a prostitute. So now you, someone who doesn't make an attempt to get one-night stands in your real life, are going to have the balls and the game to pick out the wounded gazelle in the middle of her herd and close the deal? That's maybe the way it is in the movies, but in real life, that's damn hard.
In my experience as a guy, which covers nearly all my life, girls can smell desperation like bloodhounds, and they run from it like money from my bank account. If you go in there with no wingman and the mantra "If I can't get laid here, something's wrong with me," you're going to crash and burn, and it'll be hard to get your ego off the floor. You'll stand a better chance if you're throwing money around and being the gregarious, "everyone parties with SoothSayer" guy, but again, we're not in the movies here. Besides, even if it works that'll probably be more expensive than a Pahrump excursion.
My advice? Put in some legwork before your trip and use your virginity to your advantage. Use a dating/networking site like Craigslist that has a "casual encounters" section. Post your scenario and the best picture of yourself you can find. Be honest, self-deprecating, and charming. There are women out there who would get a real thrill out of deflowering a guy, and Vegas might be the place where someone might be willing to act on that fantasy. The key is finding the girl who's into that. Some random, drunk girl at the bar is going to want a guy who knows what he's doing. Even if you've read all the books, that ain't you. It's not really fair to the girl. Plus, the first time is awkward no matter what; the last thing you want is her asking if that's it. If a girl knows what your situation is going in, she'll be understanding.
Champagne for my real friends and real pain for my sham friends!