... I know that Loki is recruiting for
The Warlock of Firetop Mountain... It's rules based, but if I know Loki in the least little bit, it'll most likely have a freeform feel and you probably won't notice the rules too much.
Also, Darren has a game in the works called
Footprints: Corruption in Tithuana that looks interesting and, if I've read everything correctly, so far, "rules lite."
I'm sure there are others looking for players but those two are freshest in my mind ATM. Check out the recruitments for these two... shoot a PM to the GMs if you've got any questions... and see if there might not be a fit.
Of course, if nothing else, you could always start one of your own... the way you write, I'm sure that you could head up a pretty spectacular freeform romp of your own.
Best of luck,
Eol