You can run USB Loader with 3.1. You will need a few of the newer IOS such as 38, 53, 55, 56.
Updating to 4.1 using this guide http://www.wiihacks.com/recommended-...l-working.html will bring you to 4.1 with all your homebrew intact and give you SD channel and VC/Wiiware SD storage.
Dual layer games on USB loaders work.
Most of the tutorials on here are about softmodding even though quite a few of us use chips too. Chips are fit and forget.