The GA-0's are the best cables I've ever heard, period. I presently have them in my two systems with stunningly good results. Unfortunately, I don't believe they make them in long lengths due to their construction.
Then again, the Audio Metallury makes excellent speaker cables in long lengths. If you could get by with using shorter GA-0 interconnects and longer speaker cables it could be well worth your efforts to change your setup around that way... You could call Sandi at AM and ask her advice.
I believe AM offers a money back guarantee if you're not satisfied. In my view, they don't have much to worry about.