Also if I ultimately want to stack an APO guide scope will the CG5 be heavy enough to support the weight? I figure it will be close to 20-25lb on a 30lb mount, will that be too much weight??
I'm currently carrying about 24 lbs of gear on my CG-5GT mount. See HERE.
And here are some images taken with the setup:
North American Nebula
Unfortunately the weather hasn't been favorable enough (along with my schedule) to image in a while, but everything is ready to go. I've been imaging at about 320mm focal length with no problems. When I do get out again, I'm planning on going a little deeper with the C6 SCT which is about 960mm focal length (with an f/6.3 focal reducer).
HERE is the native PE of a brand new CG-5 I acquired last fall...strictly out of the box with no mods. The next time I go out I will also record the PE with the autoguider running to see how well it can be autoguided.
If you can afford the CGEM, go for it because it will give you the most room to grow if you want to go with longer focal lengths down the road. If you're on a strict budget, the CG-5 will be very adequate to do significant imaging providing the mount is not overloaded or imbalanced.