hey there!
we have done several STP designs + script integration...
you will find some of them on our portfolio here:
http://adultdesignkings.com/htm/types.htm
the costs depends a lot on how custom you want the site to be and how many features you use... its not cheap but its really worth it...
hit me up on icq if you want to discuss anything.
cheers.
thy
icq 86670976