We can help you out here. We have a perfect server for you in the cloud with enough power and speed to run an effective forum.
here is an adult forum running on our server which only cost $14 per month.
http://rosasidan.ws/rosa/forum/
you can see all our packages here
http://diploy.net/pricing
We can install the script for you and also do the server setup.
Hit me up on icq so i can set you up.