Here are some links that may help with some relative guesses:
http://www.tsimportedautomotive.com/Swabarra.html
http://www.1speedway.com/swaybar32.htm
My SPF had a .79 front swaybar which is small but the effective length is only 19" and the arm length is short too, both of those make it a higher rate. The rear was .72 but it has a longer arm length and 28" effective length.
I made 5 different size bars for my front and have 2 different Speedway 32" splined bars for the rear. I plan on testing rates by using a scale and a jack in the next 2 weeks. So far I've been doing seat-of-pants testing. The testing was complicated by a tight limited slip which caused pushing in tight turns. I just replaced that with a Torsen and now I can get a better feel to adjust swaybars. Are you about to make some changes to your car? I'll be glad to share the rate results.