Agree on the 4G and Co focus. The Co focus is softer, but the 4G is OK for me and seems to last longer.
Fed's setup as last I read about it was Wilson NG with ALU rough at something like 49 mains and 47 crosses, depending on which article you read. Wilson sells this as Champions Choice. I tried it and like the 4G better.
I would try the co focus first, and if its life is too short, try the 4G. I string at 50/48 and these are the most delicious stringbeds I have ever felt when I manage to find the sweet spot.