I am out in the Berkshires and there are lots of places to get seeds and sprouts but my favorite is Clear Brook Farm is Shaftsbury, VT. It has an amazing selection of veggies, herbs and flowers, plus their website is a treasure of information.
Clear Brook Farm: Sites We Like
They are seasonal and won't open for another month or six weeks, but there is a path between my house and their farm. They sell the best local produce during the summer, including heirloom tomatoes, and exotic varieties of most common veggies.
Winter is more bearable thinking about being able to drive up there soon.