Hi Chris,
Did you know that if Lunar photography is what interests you, then all you need is a dobsonian mounted Newtonian? There are many people who only do this type of photography, many of their solar system pics are posted here in IIS. The good thing with this technique is that you don't need an equatorial mount to track. Rather, you take a short 'film' of the object as it drifts through the field of view, and computer software does the aligning for you.
Mike Salway, iceman, has a great article on this:
http://www.iceinspace.com.au/63-201-0-0-1-0.html
The is also another article in the "projects and Articles" section which describes how to convert a webcam into an astrocam. Did it myself too. Here too are a couple of single frame shots I took of the Moon and Jupiter taken through my 5" Celestron C5. First, the webcam conversion:
http://www.iceinspace.com.au/63-431-0-0-1-0.html
This mode of astrophotography will accomodate a very large aperture scope, without the expense or complication of a large eq. mount. GSO offers upto a 16" dob for less than $2500 through Andrews Communications, plus 10" and 12" for considerably less. Click onto the GSO heading:
http://andrewscom.com.au/site-section-10.htm
If you can, before laying your money down, try to get yourself to a local star party to see these and other scopes in action to see what you are getting yourself into, astrophotography or not.
Just something to consider.
Mental.