advice on 80mm set up

Looking for advice from people with more knowledge than me. I am hoping some additional funds will fall into my hands at the end of this month and I am earmarking some for a 80mm (give or take 5mm) scope. I have dug around trying to learn what I can. The scope will serve the dual purpose of a grab and go scope that I can put on a heavy duty camera tripod for quick peaks on clear nights and to travel with. Also I am planning on eventually moving into photography sometime in 2010 and have a Losmandy GM-8 mount for when the scope is used for that.

I am thinking something in the 500mm (+- 20mm) F6.5 (+-.5) range. I currently have an equinox 100mm scope and like it a great deal, but its too big for grab and go and a bit slow (F9) for photography. I mention it only to show my bias for the 80mm equinox. Anyway, my used equipment budget is in the $500-$700 range. So far I am thinking about:
80mm equinox
80mm Explore Scientific
80mm Astro Tech
Wondering if there are any scopes in the price range I am missing on my list and any thoughts on the scopes listed. Is a triplet that much better than a good double for visual, for photography? Does f6.25 or f6 make much difference for photography over a f7 (the astro tech). I really was leaning towards the Equinox, but the others really peaked my interest the more I learned about them, but hands on knowledge of the ES and AT scopes seem hard to come by.

Thanks for any help.
Matt

I've not tested any of these scopes, so cannot make specific
comments. A triplet *can* give better correction for photography
-- the chromatic aberration (false color) in the far red and violet
can be much better controlled with the third lens. But it is
difficult to generalize without knowing the exact lens design.
The eye is not very sensitive in the far red and violet,
so it is mostly a question for imaging / photography.

The difference from F6 to F7 will not be very important. You can
just expose 20% or 30% longer to make up the difference. In general
the slower lens (F7) is likely to be better corrected, but again it
is difficult to be certain without knowing the design details. Focal
reducers (typically 0.8x) can also be employed to reduce the
F-ratio. For example 0.8x would change F7 to F5.6.

Orion does have a very good return policy (EON version similar to
Equinox). Not sure about the others.

There is an older model to perhaps consider. The Orion ED-80
or the similar Celestron 80ED. It is F/7.5 so a little slower and
larger. There are many fine images taken with these, and the
Orion one I tested was superb. It uses an FPL-53 (ED glass) doublet.
The Orion version has a rather fat tube (more like a 100mm scope);
the Celestron version is skinnier.
So it is a larger slower scope, but there is a lot of info / reviews /
nice images. Maybe $280 to $320 used. But the models you mention
might be OK, too.
http://www.cloudynights.com/item.php?item_id=928
http://www.cloudynights.com/item.php?item_id=927
http://www.cloudynights.com/item.php?item_id=938
http://www.cloudynights.com/item.php?item_id=1272
http://www.cloudynights.com/item.php?item_id=1192
If you do
http://www.google.com/images
and then put in "orion ed 80 M31" or
"orion ed 80 [your favorite object]"
you'll see lots of nice images.