Ann, I also sweat a lot (really a lot) and I've found my camelback to be a boon on those long rides. If you're going for time, or if you're in an area where there are no refueling sites, it's great to prevent the lightheadedness and cramping that come with the early stages of dehydration. I fill the camelback with water (it's a 70-oz) and then use the two bottles for UltraFuel, a powder from Vitamin Shoppe. I add a little salt to the UltraFuel, also.

As for bars, I recently discovered Harvest Bars, which I really like. I cut them into thirds and eat one piece at a time. (I usually can't stomach any more than that.)

Gel is something I carry in a flask and use frequently. When it's really hot outside, I find that even if I can't get a bar down, the gel will stay down. Make sure you chase it with water, though.

Other assorted foods that work well for me: peanut butter sandwiches, bananas, nuts, dried fruit. It really helps if you can fuel on-the-fly. I drop to the back of the pack so I don't slow anybody else down (or scare anybody if I swerve).

I'm sure you realize the importance of providing your muscles with the proper nutrition, before, during, and after the ride. You can't be successful unless your engine is fueled.