Hi Daniel,
Others will provide more experienced advice most likely, but here's some to get you started!
You should have a National Geographic store near you and they sell 127SLT and 130SLT scopes: if they have one in store you'll be able to get a feel for it and check the weight etc.
You mentioned Dobs: yes, much too big to carry for long journeys but an 8" will fit easily into a normal sized car with no trouble! Advantages with Dobs is what kind of views you'll get for you money: quite superior to an SLT, and ease of set up - just wheel it out (or carry it!) and away you go; BUT photography is not easy with a Dob, unless you buy a fairly pricey mount for it.
Other photography buffs will be able to advise you regarding the SLT's ability there and what you can get for your 700 or so bucks - incidentally, that's about what a 10" Dob would cost you...
