Hi Kim,
First off, congratulations on your weight loss! That's a lot of weight to take off, and you deserve a lot of credit as it is not an easy thing to do no matter how you do it! And, given that, I totally understand and relate to your not wanting to gain it back. I felt/feel the exact same way. I have already gotten rid of all my old pants so I can't afford to! ;-) I didn't have as much to lose, but it was still a big accomplishment, and I plan to keep it off.
Your goal weight sounds very reasonable for your height, and there's no reason why you shouldn't be able to drop five more lbs. with cycling and eating sensibly.
I do understand your thoughts re. sugar. It is hard to eat high carb but lower sugar during rides, especially. One suggestion would be a whole grain bagel with peanut butter. The peanut butter provides protein and fat that seems to give me more "staying power" than straight carbs. Fig bars, as you mention, are lower in sugar than some other things you can get. At health-food stores, you can even find whole wheat fig (and other) bars to avoid the white flour, if you prefer.
Before and during riding I do not worry about carbs. Yes, after being disciplined for so long, I of course thing "gee, I'm eating a lot of carbs", but fortunately I have been doing this long enough to realize that it's not going to hurt me - I am burning (or going to burn) it all off. :-) I also must admit to going for quite a few simple carbs immediately before, during, and after riding. For instance, before weekend rides I'll have a big ole stack of pancakes with fruit and syrup! During a ride I'll have cookies or a Payday bar (or both, if it's a long ride), and after the ride, I'll have a full meal and ice cream! But then the next day, if I am not riding, I'll have eggs for breakfast and keep carbs lower/moderate that day (salads, chicken, veggies, and the like).
Sometimes I'll weigh more on Monday morning (after a couple longer weekend rides) than I did on Friday, and if so, I usually attribute it to some water weight gain from the carbs. Usually a couple of days of watching carbs (but not cutting them out completely) enables me to lose that pesky lb. or two. Overall, though, my weight has not fluctuated more than 2 lbs. this entire summer. If it ever goes up more than 2 lbs, I would cut back more, but so far I have not needed to.
Also, as for beverages during rides, I generally stick with water for rides of less than an hour, but I always have a snack before the ride (often a "Balance" or "Zone" bar, which is a more equal balance of carbs, fat, and protein) so I don't run out of fuel. For rides of 90+ minutes, I start with water (one bottle), then switch over to Cytomax or Gatoraid. Once again, it hasn't caused me any problems. I do feel a bit guilty for consuming such a large amount of sugar compared to when I was stricter about carbs, but it has been working for me so far. As I said, I'll have to start cutting back more come fall, when I can't ride after work any more.
Just for your comparision, I generally ride 25 miles after work Tuesdays and Thursdays and do a Wed. women's ride of 17 miles. On weekends I tend to ride about 45-65 miles one day and 30+ miles the other day. I ride pretty intensely in an area of rolling hills (central NC), and average around 16-17 mph. The longer and harder you ride, the more carbs you burn and can eat!
I hope this helps!
Emily