Great to hear you're wanting to get into it. It's addicting and you'll love it! My Rem 870 has I think a 22 or 23" barrel andtwo beads. Just line em up and shoot. I would recommend a barrel shorter than 26", just for convenience. I've never had adjustable sights, so I can't say much about them. As far as your question, how important is it to have adj sights? It's not at all. You'll find out when you hit the turkey woods that having a nice gun helps, but it's not your most important tool. Good luck and happy gun shopping!