Hi Wayne, last year I upgraded my Evolution 6" by fitting a 9.25" SCT OTA to it (bought second hand on this website). The Evolution
mount can easily handle the extra weight, but the tripod that comes with the 6" is not as happy, normally the Evolution 9.25" comes with the tripod that is normally included with the CPC 925. Having said that, I found it still works really well and I'm getting a significant improvement in my planetary images using the 9.25".
My main focus is
planetary, but I've also had some small success imaging a galaxy (
NGC 1566) but it's a
lot harder with an alt/az mount since you cannot guide with the Evolution, it doesn't accept ST-4 connections (and don't try, as you could damage your mount).
Outcast's post above is excellent, the only thing I would add is to watch these excellent
tutorial videos on how to image and process the planets. I don't use a Bahtinov mask for focus, instead I use one of Jupiter's moons for Jupiter, the Cassini Division for Saturn and the planets themselves for Mars, Uranus and Neptune.
You will also need a program to capture the videos from the camera, for the Nexstar I would recommend FireCapture and for the DSLR I would recommend BackyardEOS (for both planetary and DSO).
If you are thinking of upgrading to an 8", have a look around for a good second hand 9.25" instead. Might cure your aperture fever for a bit longer
.
Andrew