Welcome to the NH forum, and eventually... to New Hampshire
The things that you mention on your list are all doable in many of the towns in southern NH, and Londonderry is a great place to look. Both Amherst and Hollis are more rural, unless you are near one of the shopping areas (Rte 101/101a in particular).
Because you mentioned a preference to town water & sewer, you should probably be aware that residents in this area (I live in Londonderry) are discovering that the roundwater that supplies many of our wells (and public water supplies, for that matter) are suspect for having been contaminated with PFOA, a by-product of the plastic & coatings industry. While the problem originated in Merrimack at the St. Gobain facility, the chemical is being found in other nearby towns. In addition, a recent discovery that a (now closed) manufacturing facility in Amherst has also been associated with elevated levels of PFOA, and they are in the process of trying to determine how widespread this additional location of PFOA has traveled. The St. Gobain issue has been in the news for the past several weeks--this new location in Amherst was just made public in the last couple of weeks. It's always something...