Sirius Optics sell Intelliscopes. Website prices here:
http://www.sirius-optics.com.au/Orion Dobs.htm
At those prices you'd probably be better off buying a GS or Synta Dob and fitting Argonavis.
Scope's limiting magnitude depends on visual magnitude, and the difference between visual and scope limits depends on pupil size so there is enough unknowns there to give an uncertainty of around 1 mag.