You need to tell us what kind of distances you are hoping/planning to ride for your tours. If you are not packing much for panniers, etc, does that mean you'll be staying in motels or B&B's?

Large range granny gears, fenders, any racks, steel frame, sturdier tires, extra water....all these things will add some weight.
The good news is that if your touring bike winds up being 25-30 lbs (without panniers), your granny gears will help you climb the hills anyway despite extra weight. You will also develop stronger legs to get that bike moving. Most people who like touring are not too concerned with high speed, and pedaling a 30 lb bike on flat terrain is not that much more effort than pedaling a 20 lb bike on flat terrain.

Hybrids are good, tend to be comfy with semi-upright position for long rides...but they often come with straight bars which can be a strain on hands and wrists on long rides (40+ miles). Drop bars allow many varied hand positions- and believe me, after a few hours riding you really are grateful to be able to vary your hand/wrist positions.