Nick, if you are handy, you can turn these:
into these:
and then use any racing spring you want, plus adjust the ride height to whatever you want.
PM me if you want to see what's involved - basically a mediocre lathe and a little time, buy the threaded sleeve and spring cap from any race shop, and choose springs. I have a spare shock that leaked if you want to practice, plus I think I have parts I practiced on.