Congrats on your 870. Fine weapon and good platform to
build on, if you want.
Check JD's page at www.aiptactical.com
He specializes in 870's and can do anything you want or
give you some good advice. Lot's of good reading on his
web page also.
He can parkerize your parts, swap barrels, beef up the inside,
and may have some used stocks and such around if you
want to change something. Good luck.