Like jack19512 said, it's a personal choice.
The m48 is scarcer and is a little bit tougher to find. Both are readily available now, but I think if either one is to "dry up", the m48 would be first.
For hunting, no comparison, go with the m48. Without starting a huge deal on 7.62x39 VS. 8MM deal, the m48 is FAR superior for hunting.
Also, with the shortage of 7.62x39 ammo, get the m48 first. If $ and everything else falls into place, then get the SKS.
I had an SKS and a ton of ammo a few years back. Shot one deer with it and plinked alot too. It was fun and all, but my M48a is so much more versatile. I sold the SKS and since have picked up 3 more 8mm rifles of different types. My future deer,elk,bear,moose,whatever rifle is a 1949 8mm sporter. It's agreat round and ammo's readily available.
This year deer hunting is with a m48a with an iron elite scope mount (attaches to the rear sight so nothing original is lost) It's a bit heavy, but shoots moa with S&B 196gr SP ammo.
Alright, I'll stop, but I'll just say 8mm, 8mm, 8mm, 8mm, 8mm