Titan,
I have been digging through the site looking at reviews and comments on the newer SE series. One user
Greenswale loves his 6" SE, it fits your budget and is nice and portable. (With the change from the 2k, you can get a power tank,
Power supply for a Celestron Nexstar)and a couple of extra eyepieces.
Another article,
small SCT vs big Dob - Paradox?
has info on smaller vs Dobs, it also refers to an external link on 6 " scope & performance. (If you have not already seen this).
http://www.geocities.com/the_150mm_reflector/
Not an answer on the 5" or the skywatcher question, however hopefully some help on the decision.
Michael