I happen to live right next to a brick and mortar Sparco store, was able to sit in their whole lineup.
I'm 5'10" 170lb, and the Chrono Large was far too big for me. I actually found their cheapest offering, the R100, to be the best fitting and decent quality on par w/ the Chronos.
The R333 and R600 were also excellent if you're feeling spend-y.
Guess I'm saying: see if you can find a motorsports store / distributor in your area to get your own butt into some alternatives.