Bought the Colorado XT two weeks ago and have had it out 3 times. First time was with just oars. Then I bought a 30 hp Minn Kota . It's very comfortable for many of hours of fishing but with any wind it will drift badly because there is no keel. I've found that my float tube fins are helpful in stabilizing the boat so I can concentrate on fishing.
I have an older model Fishcat. I float the A section of the Green and just got back from the Big Horn. You definitely need a rod holder or two. I have two rods rigged up at all times. One rod with nymphs or streamers and another with dries. I use fins on the rivers to help hold me in position to cast to pockets and seams. You can troll on lakes using your fins. Be careful with the fins when landing. You can't walk forward in them. You must wear a type 3 or better life jacket on the Green and Colorado. You need to have a type 3 life jacket on your boat for the Big Horn ($80 fine). I would advise you to carry a spare oar in case you break one. If your boat comes with 6 foot oars, I would recommend you get 7 footers. The difference in power is amazing. You might want to buy a set of oar rights. They help you keep your oars at the correct angle when rowing. You can get them from Outcast or Oar Rights. Be careful using an anchor in moving water. It can be dangerous. Make sure to carry a sharp knife in case you need to cut the anchor line.
A few weeks ago, I wrote a novel on accessories for my pontoon. Search it out…
As for comfort, I have two suggestions… You can probably mount any boat seat to your pontoon. They all use a four bolt/screw install. Look at the Tempress low back folding seats. They are much more comfortable than the stock seat the pontoon comes with. But they are not cheap. Other than that, breathable waders, wader fleece, Power Dry bottoms, and multiple socks all chosen for the water temperature. Not much else you can do for comfort.
Already mentioned, but I'll reinforce, if your oars have those silly rubber donut oar stops, throw them away and get Oar Rights. Blade rests also help a lot. I also expanded the storage on mine by getting a pair of larger bags to replace the minimal ones that came with the boat.
I'm not sure if the picture came out? My personal pontoon, 8'X4' NRS Gig-Bob, 2.5 HP Suzuki 4 stroke, anchor four tackle pouches, rod storage for 4 rigs, GPS/Depth Sounder, water temp, flippers, air pump, net, gear storage behind seat, over 400 trips in four years with no problems.