Thanks for the suggestions folks. I went to a local camera store today and looked at a Tokina 90 macro and a Sigma 105 Macro. The Tokina was used, older and not in great shape so I couldn't use it to compare. The Sigma 105 was close to $600 and considering the Canon 100 2.8L IS USM is on sale (until midnight tonight) for $749, I pulled the trigger.
I am pretty dedicated to B&H but Adorama tossed in some free accessories and had a kit for a few bucks more that includes a focus rail, although who knows how well it will work with a 100mm lens.
Now I just have to wait for shipping.