Also how long would this realistically last me?
Fecking ages.
Unless your a complete wash fiend, I would say that kit would last about a year. Collinite is awesome stuff, and the beading has so far lasted ages on my car. I have found that "easy on-easy off" top-up spray waxes have been much more effective post collinite as well, so the need to completely re-do it is far less.
Two things...
1) Remember to get some decent microfibres to polish with
2) Get a clay bar (I recommend Sonus Green) and detailing spray as lube to prep the car before you polish and wax it.