I would think the OP is looking for a model to these shots for fun, maybe build a business or rep out of it? So he's the client AND photographer and a good model will ask for pay or not play.
My last model charged $50 for nude, $70 for erotic (she's a dancer and also does adult movies). I hired her for two hours for a rate in between since I'm not interested in "spread" shots but things definitely went more into erotic than just nude. She was great to work with and I'll hire her again for sure. I got about 1500 photos out of two hours and a LOT of them are keepers (last 8 on my site are her, have many more in many more poses) so I go a lot out of it. She also had to travel to the studio.
Generally I'd say the rate is between $50 and 100, most models negotiate (speaking of MM models, the only source I use with nothing but success so far)
Now, all this is a hobby for me, I don't run a business and don't need to make money off of it (though I'm considering that for the future). If I were a pro and a client wants some photos, they pay for everything (or I'd roll the model cost into the sales price), if a model contacts me I pay nothing but give her photos she can use for what ever (i.e. I give her a full release but she has to credit me). She only gets finished developed photos I select (so I can keep what I want for myself) and never gets the raw files or unedited photos etc.
Also keep in mind that many models say pay only but change that if they see your work and think it fits their port (and there are quite some that are in dire need of good photos) so just ask or send out a casting call, explain what you want and see if a model bites.
Agencies are great, but that's pro level for paid work, from how I understand your post that's not what you're after right now.
Hope that helps?
Oh, I also sometimes hire a model together with a small group of friends and we set up a group shoot of two or three hours. Model rate is shared among us, we have a lot of fun, always learn something and those that don't shoot right now can help with lights or hold a fan or reflector or throw balloons at the model etc