First off those spring loaded faucets are crap, and probably coated with stainless steel, and over time, that layer will wear off inside the faucet exposing the brass core its wrapped around on the plunger, which in most cases will give your beer a off taste. What ever faucets you go with, make sure they are totally stainless steel (those are always more expensive then the coated ones)
To clean the guiness line if you buy one of those bottles you have to make sure it has a hookup for the European coupler, your best bet is to just buy one of these and get two hook ups on it, one for normal couplers and one for the guiness , there is a 2.5 gallon model (pictured) and a 5 gallon model, same size as a sixtel of beer
Micromatic makes the best coupler and faucets for guinness, so goto their site to find those , perlick makes a guinness coupler but its crap in my opinion
The slow pour faucet for guinness and other nitro beers arent front or rear sealing , its totally different than normal faucets, get the micromatic one here as well.
Also you need a 75/25 nitrogen/c02 blend to run guinness, dont try to run it off of c02, it will taste horrible and make the keg go flat. At the same time dont run normal beers off of the 75/25 blend, your keg will go flat. So basically for guinness you need to run a separate gas source for it.
Ditch the spring loaded faucets all together, its a gimmick so you dont have to push the handle back when finished pouring, we call those the lazy mans faucets in my line of work (im a draft technician lol)
At a minimum you want to can your lines every month, the brewers association suggests every 2 weeks because yeast and bacteria start to grow in your lines at about 1.5 weeks, but on a kegerator where the lines are short once a month will suffice. Ive never used the cheap line cleaning materials and equipment so i cant comment on those, but stay away from the powder cleaners and use only approved liquid caustic and acid cleaners. Acid line cleaning is done 4 times per year(once per quarter) it removes beer stone where as caustic cleaners do not.