A loaded question, Jim. You may want to decide on what size SCT you want first. From what I have seen from the experience of those with 11" scopes, guiding starts getting tricky if you are doing deep sky imaging. You really need a steady mount for the long focal length and the tinier objects you'll be going after. I've seen some reports that there can be disappointment that the local seeing conditions can work against these large apertures.
Of course there is the temptation to place all your scopes on one mount and have them all ready to go. But you need to consider flexure and that the greater weights will be flexing all the connections and whatever brackets you might select. If you go side by side that might be an option if you pick some good hardware. Over and under puts a lot of stress on the base scope. And with all the counterweights with a multi-setup you need to control a large mass with precision.? ?
With my G11, I use a C925 during winter and spring to capture galaxies, then switch over to a 102mm refractor for the summer with all the large nebula targets. Sometimes I do a side by side with the 102mm and a 60mm on the other side. But I really would not try mounting all these things all at once due to the complexity. If you start having guiding issues, it might be harder to nail down the solution.
If I were to get an 11" SCT, I would get a Titan just for that, to better manage the payload. But I think the Titans are way backordered right now with the high G11 demands at Losmandy.
Hope this helps.
John
?
