"...not enough stock for me..." That's not a left/right issue. That's a stock length issue. Pachmayr makes a slip on recoil pad that'll add an inch. Plan 'B' is a bunch of spacers under the butt plate. You'd have to make 'em though.
I've been shooting every long gun left handed for eons with no fuss. Never had an issue with hot brass. Had an M1 Rifle clip eject straight up and come down past my face on at least one occasion though. Shooting glasses are essential.
If you want to play with milsurp bolt actions, you'll just have to forget what side the bolt handle is on and just shoot. Otherwise, for a bolt action buy a left handed bolt or just shoot a right handed action left handed.
Lever actions are ambidextrous. If a semi is ejecting properly, the hot brass will fly over your right shoulder.