I have an 8" GSO Dob - I like it, although I really wish I'd gone for a 10 or even 12" though. I don't think the difference in size between the 8 and 10 is enough to justify the 8 on compactness grounds.
As you are already leaning that way, I'd get the 10.....
.....and if you aren't planning on lugging it around too much, seriously think about a 12, as you know you'll want more aperture very soon anyway!
