I dont think you will find another freerace sail on RDM mast in size 7.5
There are a few Race-sail options, but you have to be a bit handy.
You can convert (I have seen/done):
-Gaastra vapor 7.6 (2007)
-Naish Stealth 7.0 (2006/2007)
-Arrows maxx speed 7.5 (is standard on RDM)
-heard of severne Code red on RDM? dont know for sure.
In theory you can convert every SDM cam sail to an RDM sail, only thing is that the total shape will change. There is always something good and something worse, most of the time alternatives reduce the windrange of your sail.