I have a similar setup for 'round town use, I took the granny off the front ring (I would have left it on just cause but the derailleur I had laying around could only handle a double) and I changed the rear cassette to 11-21. Technically you have the same gears almost with your 12-25, but I had 11-30 and I like the closer spacing of the other one for road use. Mine is a bit older though too I should mention, and I have 38-48 rings. I bet you could score a crank like that pretty cheap, or just get the rings and swap it out (mine is 110 too)
+1 on the tires, that's going to make the biggest difference. I run 1.25" wide Tioga City Slickers which are cheap and durable.