If you think if your going to image in the future then either the 6 or 8" in the Celestrons as when funds are available you can accessories either with a Hyperstar lens to give wide field F2 images as well as standard native F10 or F6.3 with reducer.
An 8" will be better than the 6" when it comes to planetry or deep sky observing but both will be portable enough.
Both will have plenty of aftermarket goodies to add on.
I am not a big fan of the single sided arm mounts when it comes to adding extra weight of cameras ect as well as the fact you need to add a wedge for long exposures. Better a GEM mount either a Celestron or an Skywatcher EQ5 pro or bigger mount. Plenty of help to go around on these if required. Don't skim on the mount either , better a 6"scope and heavier mount than an 8"and an undersize mount.
The best bit of advise would be go along to a club or an INS members viewing night and ask lotsa questions and look through as many scopes as possible. There will more than likely be a 6 or 8"SCT there.
Mark