You seem to be on the right track with the higher frame rate and number of subs you're stacking. Most planetary imagers with SCTs use an effective focal length of between f/20 and f/30 to get better image scale on the chip, so investing in a quality 2x or 2.5x barlow would be a good plan. You should read Paul's excellent processing tutorial here
http://paulhaese.net/planetaryprocessing.html