Here in europe you can get heavier 9.2 and 9.7 springs. A friend of mine has the 9.7 and is absolutely happy with it. Before he tried PDS4 but he could't get the sag dialed in properly...right now everything seems to be fine.
Another one I know has the same and had even more muscles as you have;-) and he had this 9.7 spring in his husaberg and was very happy with it. As I know this is the hardest spring you can get. I would give it a try!