Custom astrograph on a GOTO mount

Hi,
I have a question for GOTO mount veterans. I recently acquired a B&L 508mm, F5.6 telephoto lens. When used with an ST6 camera it delivers 44'x58' fov. Whole setup is less then 15lbs. I intend to monitor long term variables and do a little bit of comet search. I want to buy a goto mount to do the work while I enjoy my TV or a good nights sleep.
I am pretty sure Losmandy GM8 with Gemini will handle this setup just fine but I am a bit concerned about the price tag.
I will like to know if I will be happier with a Meade LXD75 or Celestron CG5 GOTO. Is the money spent on GM8+Gemini justifiable? Can I enjoy long years of service?
Thanks for any opinnions/suggestions.
Alper

If you are even thinking of getting into astrophotography, put all your money on the best mount you can afford. It's already hard enough with a good mount. Why make it even harder on yourself by going with a cheaper mount. Although there are plenty of people taking pictures with cheap mounts, it's just easier with a better mount.
Ralph