Congrats on the new purchase
My experience with the GSO RC-12A has been quite positive. All I need is a string of clear nights to actually start taking some photos and I'll be a happy chappy but this winter is turning out to be a cloudy one
Some on these forums have a great amount of experience setting these scopes up. They are fantastic.
My rig uses a Paramount MX which handles the weight really well. I can thoroughly recommend the MX. Have not handled an MXII but I hear it's an improvement on the MX with better motors - so I'd recommend that too.
Likewise I used a Tak collimating scope and that has made collimation so much easier - takes a bit of experimenting to begin with but after your first two attempts you'll be collimating with ease.
I use a 2" Moonlite with normal stepper - no need for the high res for me because you can move the focuser in micro-amounts with TheSkyX software - might be different if you are using something else but it works really very well for me.
Re the reducer - I hear that Paul Haese is experimenting with GSO to get a 3" reducer working - but I have heard some very good things about the AP 2" also. 80mm back focus is good.
Something to consider - which I haven't wrapped my head around yet - is if you want the reducer embedded inside the Moonlite (they do a version that you can do this with) so that as you move focus back and forth, the reducer moves with the focus but can be seated closer to the front of the Moonlite (i.e. closer to the back plate of the scope). This helps reduce the amount of spacers you need in order to achieve prime focus. But there's possibly an argument for putting the reducer closer still to the back-plate. Like I said, haven't turned my eyes to reducers yet.
Oh another thing - it was recommended to me to get an AstroZap light shroud - which is actually a very important accessory, far less frost and dew on the secondary and primary with this over the scope. Light pollution is neither here nor there for me (lucky), but dew and frost and not good where I am.
The scopes come with plastic dust covers for the primary and secondary, no need to buy anything additional there.
The GSO comes with a collimating ring as standard now by the way.
Here's how I set mine up on my mount:
http://www.skyslab.info/guan-sheng-o...tien-part-two/
Here's the collimation setup for me:
http://www.skyslab.info/collimating-the-gso-12-rca/
You can see from the second link - I've had to add all the extension rings bar 1 on the back plate before my Moonlite - the scope has an awesome amount of back-focus!
I presume you'll be self-guiding with the SBIG camera and don't need an OAG?
