If your in focus and the seeing is good there should be plenty of detail in that size. Mine typically run from around 130 -200 mg (typical for Jupiter) up to nearly half a gig (that's for a 2000 frame saturn though), depending on the resolution, time and believe it or not, the barlow magnification. It seems that the more colour in the image (or should I say the less black) the more megs.
I certainly hope you get it sorted, You'll definately pull some stunning shots with that rig.
