This is a lovely area, Long Buckby is a very large village with co-op, 2 Indian restaurants, junior and senior school are split for primary, library and some shops, baby swimming, football and rugby clubs, lots going on, but as it is large it doesn't have that small village feel.
Welton is really nice but may be swallowed into Daventry in future. Other options include Braunston, Barby, Kilsby, Flore, Staverton (much smaller though), Badby. Maybe east and west Haddon.
Crick is ok but a bit cliquey, has a doctor's surgery though. I'd avoid Weedon which can be a bit run down.
If secondary schools are a consideration, avoid Daventry catchment, try to be nearer Guilsborough or Rugby - so west of Barby or east of Crick.