RE: composite or wood stock?
I haven't come across a synthetic stock I have actually liked. Even HS Precision and McMillans. For a "beater" gun they are fine but I much prefer to have my guns in wood stocks.
You can make a wood stock very stable and resistant to the elements by bedding the barrel channel its full length with epoxy or other bedding compound like devcon. This will add strength to the wood and create a impervious barrier against moisture.
If the barrel is free floated by about .020" then even a regular wood stock won't swell up enough to touch the barrel and change the point of impact.