I went to Auto Sport Engineering in Stow MA for my 944. I think it is about an hour and 15 minutes from Concord NH. They have a laser alignment system and it typically take about 2-3 hours per car. I searched Rennlist and Pelican before I called them and both forums had very good things to say about this shop. It is fairly pricey ($200-$300).
Porsche service repair Auto Sport Engineering - Stow, MA