I bought the baader MPCC from Peter Tan at
http://www.tan14.com/Baader.htm price was good, and quick delivery as well.
Not sure about the GSO CC.
I'd suggest you ask the supplier to have the scope collimated before you pick it up and then you make only minor adjustments in case it shifts during transport.
ask them about the spacer as well for the CC to your DSLR.
Whereabouts are you located? if you're in Melbourne, send me a PM as i'll be heading out to some dark skies for a few imaging sessions.
For eyepieces, the GSO 30mm superview is supposed to be good with this scope. not all eyepiece work well at F4.