ISBoxer is great. Its highly customizable.

I have used a lot from Ualaa's guide. The best part is you can add 1 part at a time. My last 2 adds have been action target groups and using targeted AoEs.

The only advice I have there is categorize stuff. Key maps for example. I have several sets. When I create a keymap, it may be for all my groups, it may be for a specific team. getting it in the right map helps speed up the setup for a new time.

New teams get the "base" keymap. Then I create a separate map just for items specific to that team.