How do I decide which fishing reel to buy?

I am not a huge fisherman but enjoy fishing for b, pike, and walleye. I just found out that my reel only holds 6 lb. test line. I can't catch the size of fish that i would like to with 6 lb. test line and i would like a new reel. What should i consider before buying a new reel? also i would like to have a spinning reel.