Welcome to Bass-N-Tubes! It is a bit unclear (at least to me) if you are fishing a pontoon boat or float tube but I'll assume pontoon boat. Do you plan on fishing tournaments? Also, what type of pontoon boat do you have?
If you aren't going to be fishing tournaments then you don't need to worry too much about a live well, pumps, or larger batteries. You may want to have a fish finder available though.
I have a pontoon boat and my non-tournament setup is pretty straight forward. I have a rod rack attached to the back cargo area using hose clamps, a small battery for my fish finder, a mount for the fish finder, and another mount for the transducer. After that I just put tackle bags, a cooler, and my life vest on the back cargo area.
A good set of waders are pretty much a must if you plan on fishing winter or spring. I use breathable waders and layer up clothes under them to stay warm. Others use neoprene waders.