haven't even gotten my jamis trail xr from the factory yet and i'm researching future upgrades... what are some good tires in the < $30 per tire range which are good in rain, maybe some mud, not so much rocks and such, just city sidewalks, gravel trail, debris-ridden rural road shoulder, etc. all-around.

also, what tires Can be used on 26", 1.5 rims? can i go up to 1.95? 2.1? can i go down below 1.5 if i find a knobby cross tire i like? (as sure as i am sheldonbrown.com has the answer to that question, i figured i'd ask here.)

for starters i'm looking at:
maxxis overdrive, michelin country gravel, kendra kross, continental edge.