Antifreeze is usually ethylene glycol with some lubricants and anti-corrosion additives (and fluorescent coloring :wink:. Some is propylene glycol which is supposedly more environmentally friendly and less toxic, but may be somewhat less effective (or maybe just more expensive) than ethylene glycol. Alcohol(s) were used way back when, but I don't think any modern AFs use it.
Since the base (ethylene glycol) is pretty much the same, the differentiators are the additives (as with gas and oil). I can't offer much more, but I use a name brand--i.e. Prestone--because it's a relatively cheap investment. YMMV.
Since you use Water Wetter--which has lubricants for the water pump and anti-corrosion additives--you could theoretically use straight glycol with water, though I don't know where you'd be able to buy it (some chemical supply houses, maybe).
Like Alan said, mix with distilled water. I used to argue with people who were convinced distilled water was "ion hungry"--whatever that is--and would destroy your cooling system, if not dissolve your engine :wink:. That argument's over; pretty much everybody in the know--including "Click and Clack"--now recommend distilled.