I was in exactly the same position. I have a set of Sektor DPC's 120-150 2012.
I was also finding the spring to soft (I'm about 88kg), and had a couple of over the bar moments as the suspension was prone to bottoming out on steep stuff and tucking the front under.
I looked everywhere for a blue (firm) spring, and was told that nobody had them, and unlikely to get any more, so I had a fairly useless pair of forks. I ended up buying a set of 2013 Revs from Merlin to replace them, the air spring allowing me to sort the fork for my weight.
I've still got the forks and will use them on another bike if I ever get hold of a blue spring.
Sorry to ramble on, I guess that you should be looking at a black (x-firm) spring. TF Tuned or Loco would be a starrting point.
They're asey to fit, lots of online guides.