I doubt the 8mm will become defunct any time soon unless the dumbocrats have their way and try to ban everything. Bullets are available from Hornaday and Nosler, Remington and Speer. The 2007 Hornaday catalogs has 4 8mm offerings, 125 gn, 150, 175 and 195. My Husquavarna 8 shoots the 195s into one hole at 100m - I don't know if they are more accurate than the Nosler Accubond in 200 gn but with the same powder charge they both shoot the same - very, very accurately.
Brass - I think I got 200 new cases from Natchez Shooter's Supply.
There is a ton of older 8mm stuff available and Sellier and Bellot as well as Privi make new non-corrosive stuff but they are made to euro specs and I had to toss all my euro 8mm cases and buy American made cases to get them to work in my priming and shell holders. HTH. Mikey.