Wow - that moon shot is a cracker! The blue looks so much more restful that the usual black. You might be new to other styles of astrophotography, but you obviously know your way round your camera.
Your 100-400mm Canon lens sounds very juicy. I couldn't quite stretch that far at the time, so I bought a cheaper 120mm - 400mm Sigma version instead. I found that it was a bit too heavy to use hand held for taking bird shots, and they were often reluctant to sit still while I got a tripod set up and adjusted! So I also got a cheaper Canon EF 70-300mm lens which now lives on the camera and can be comfortably hand held. Very versatile and ideal for most of my needs.
What else moves in your yard? Birds, bees, flowers, roos, kids?? I just discovered that there's a sub-forum here for terrestrial photos - nature, and whatever else. Maybe you could post some there? I certainly intend to bore the members with some of my pics!
Good luck with find the right attachment. The one I bought was something under $40 at the local camera shop and it's quite slim. I unscrew part of the viewing tube and screw the adapter on instead, which gets the camera close to the telescope. Apparently, if the length is wrong it can be impossible to focus the image onto your sensor. Naturally, you have to use the focus wheel on the scope as the lens has been removed. In my case it worked OK, but it was almost at the outer limit of adjustment.
Cheers,
Chris