HL, since you're wanting to get to a dark sky, why not make it to a local star party (check the forum here in IIS, or the club directory in the 'Resources' heading at left). This way you will see many different scope, how big they are & how they perform, before you drop the big bucks.
But do learn on the 8" first, as Erick said. It is an easier scope to handle than a 12".
& if you do get a Hummer, what 12"? 20" dude,
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