If you do a collar, it makes lines in/out MUCH easier then worrying about killing your freezer.
You will need a secondary regulator, or another primary regulator 'daisy chained' of your current one in order to have different pressures (check out MicroMatic.com, Kegerator, Draft Keg Beer Equipment, Taps). You can then hook a manifold/distribution block on the one for all of your beer connections (these will all be the same pressure).
Recommend spending the money on perlick faucets from the get go; cheaper to get them now then go cheap and buy them later. With four kegs on tap, I'm pretty sure the typical faucets will get stuck with out some care/attention.