Glucose tabs are good but they taste sucky. Smarties are pretty good... 2 small rolls of them are basically 15g of carbs, mostly dextrose. They act faster than runner's gels, because they don't have ANY long-chain carbs (like maltodextrin) that slow down absorption.
Peanut butter is not a good idea. It's about half fat, and the fat will slow the absorption of the carbs that ARE in the peanut butter.
I have had a VERY positive experience with my CGMS. In fact, this past January when I ran a half marathon, I stopped at the six mile mark to test my sugar with a BG meter, but got a temperature out of range error (it was 28 degrees F the day of the race). So I was forced to rely for the next 7.1 miles on just my CGMS. I finished the race at 2:35 with a BG of 100 mg/dl. I could hardly have hoped for better.
CGMS won't replace meters any time soon, but it's FANTASTIC for trend data, and I find that I "micro-bolus" more and it keeps my sugars more in line than with just the BG meter.
The CGMS sensors are disposable and cost about $30 a piece, for about 3-5 days of use, and give a BG reading every 5 minutes. The transmitter that picks up the readings and sends them to your pump is around $1000 and not covered by most insurance. Upgrading your pump to be compatible with CGMS may be required. If so, that will cost around $700 (that's your co-pay, by the way) and the rest (around $3000-6000) will probably be covered by insurance if your pump is old enough. Talk to your pump rep if you can't get upgraded... they can often work miracles. :-)
Good luck! Sorry about your lows. Hope you are better now.
Oh! The one GREAT thing about CGMS's is that since it automatically reads your sugar, it will ALSO tell you automatically if you are low or high, with an audible alarm.