Cabin wall insulation

Same guy with shack, trying to make it a cabin for a few years before retirement. Previous owner has roofing felt on the outside of studs and on the inside. On the outside, he put real 1" x 10" pine boards with gaps that were filled, incompletely, with spray in foam (greatstuff?). I plan to put an exterior paneling around the outside. Do I leave the roofing felt on the outside or buy something like Tyvec? Can I put the 4'x8'sheets of foam around the outside and then the paneling on top of that? Any help appreciated.