 Re: outboards
Much will depend on how much your wallet will tolerate, what body of water will be running in, dealer network in your area and what sort of performance (or lack thereof) you are willing to settle for. First, I would suggest that you put as much HP on it that you can comfortably afford, up to the max rating, particularly if you are operating in a body of water where currents and wind is a constant factor. Most pontoons will only perform to a certain speed any way, but you may need the additional power to combat currents and wind, particularly if you have a bunch of weight on board. You will also need the higher HP if you would like to tow a tuber, wakeboarder or skier. The suggestion of Mercury's Bigfoot is a very good one. If you are on a lake the 60-HP Fourstroke Bigfoot (as suggested) would be an excellent choice, as long as you will not need, or want that extra oooph.
Take a look at the availability of servicing dealers in the specific area where you live and/or be doing your boating. While Tohatsu and Suzuki make a great motor, they lack the dealer network of Mercury, Yamaha and Evinrude/Johnson.
Next, narrow it down further by deciding on if you want a four stroke or a two stroke design. If you should decide on the two stroke and want the the availability of service and parts, it will be hard to beat Mercury's Optimax in either 75 or 90 HP versions. If you prefer the four stroke, then I suggest you consider Yamaha.
This is not to say that the other makers are not as good, and in some cases (possibly) better. But, the availability of service and parts should never be discounted or overlooked. Good Luck! | 
