At the risk of upsetting a lot of people on this forum, can I be so bold as to point out that a SCT is not necessarily the best choice if your prime interest is in astrophotography? I would agree with Ant's suggestion...Why not get as good a mount as you can afford, an ED 80 and a canon 350D as your entry into astrophotography?
Take at look at the presentation made by Chris Venter at the South Pacific Star Party where he says pretty much the same thing;he also has some suggested configurations for various budgets
http://www.dslrfocus.com/support.html
(click on the link to the SPSP presentation to view a copy of his Powerpoint slides)
Once you have a good mount then you can always upgrade your OTA later. A premium apochromat, or if that is out of budget, a Maksutov Newtonian -(just look at the fantastic work Eddie Trimarchi does with his Mak-Newt, plenty of examples in this forum)-would be I suggest better choices for an OTA compared to an SCT
After all Phil Harrington has this to say about SCTs in Star Ware (quote reproduced from another forum):
"What about optical performance? Here is where the Schmidt-Cassegrain telescope begins to teeter. Due to the comparatively large secondary mirrors required to reflect light back toward their eyepieces, SCTs produce images that are fainter and show less contrast than other telescope designs of the same aperture. This can prove especially critical when searching for fine planetary detail or hunting for faint deep-sky objects at the threshold of visibility."
"Image sharpness in a Schmidt-Cassegrain is not as precise as that obtained through a refractor or reflector. Perhaps this is due to the loss of contrast mentioned above or because of optical misalignment, another problem of Schmidt-Cassegrains."
I am still waiting to see what the new Meade RCXs can deliver in the hands of amateurs, but in your budget that may be worth considering..
my 10 c worth