sounds like a hybrid or a comfort bike. they have similar geometries, but a hybrid is a bit more of a road bike -- larger wheels with skinnier tires -- and a comfort bike is more of a mtb -- smaller wheels with fatter tires. i suggest that you look at hybrids. both styles of bikes are compromises, but the hybrid is less of a compromise and, for some reason that i fail to understand, hybrids seems to have better spec for the price.
- short trips around cycle paths in city
- longer day rides on roads
- ability to have panniers on bike and a baby seat - will be carrying a small child sometime.
- don't really like the MTB style of sitting - would prefer to be more upright.