My advice is:
Buy once, cry once.
Most firearms and accessories can be pretty expensive and like tools, you get what you pay for. I will use optics as an example, if you are looking to get a 4-16x40 scope for your rifle you should save your beans and get something decent as compared to an el-cheapo model (aka NC Star).
The SKS is a super fun rifle, cheap to own, and cheap to shoot. The biggest problem is all the time it takes to clean it after shooting some surplus ammo.
The CZ457 is a sweet rifle that you cant go wrong with.