Dude, has anyone ever told you that you have trouble making up your mind? ;)

I'll try to answer some of your questions.

The super fat cat is definitely a nice float tube but 300 bucks is WAY too much dough to spend on a float tube. The day tripper is a very high-riding tube with less drag than most due to the fact that it has 2 pontoons and no back(middle) section in the water. It's actually more of a hybrid pontoon/tube than the fat cat is. Woodsac
is the guy you want to ask about the day tripper.

If you are looking for more speed on the water you should definitely go with a pontoon boat. You could also pick up a decent float tube for under $100 for those times you need to hike in to a spot or carry it for long distances. I own both a tube and a pontoon and have only used my tube once in the last year and a half since getting my pontoon boat.

Here's what I think you should do:
Go to www.outdrs.com and buy the Creek Company ODC 816 on sale for $259. I looked at your profile and see that you live in Texarkana. Living in that humid climate, you don't want to buy a pontoon boat with a steel frame because it will eventually rust. The Madison has a steel frame along with questionable pontoon design(IMO). The ODC 816 has an aluminum frame, 8 foot pontoons with tough covers and liners, and weighs only 45 pounds. The ODC 816 also allows you to move the frame on the pontoons for proper balance and weight distribution which the Madison does not. Don't place too much stock in any review you read about it. I have never heard anything bad about the ODC 816 and would consider it an excellent choice for your first pontoon boat. If you still don't like the ODC 816, don't get the Madison! Browse the outdrs.com site, they have some good steel-framed boats by Outcast and WaterSkeeter that are much better boats than the Madison at comparable prices.

Take your time and buy whatever you think best fits your needs.

Doug