Woah, nice work! Next stop, steam!
According to an interview in March, gamersgate take a 30% cut, the same as Stardock take if ordered through their website. However, Stardock allow game devs to add a buy button to their own website, and when people buy through there, Stardock only take 15%. So... if you want to help CF get the most possible money, do that. If that option isn't available, then buy wherever you prefer
Out of interest, I've not used GG, how do they deal with redownloading? Do you just log into their website, look in your account and have a download link there?