Pipeline........the most important thing to have as a brewer.
I use a single regulator to serve two taps, and can carb 2 additional kegs at the same time. I can store up to 5 in my fridge. As long as the beers you tend to drink have close carbonation levels a single pressure will be fine.
As far as maintaining the pipeline goes, I have 5 kegs, and generally keep something in the fermenters at all times (10 gallons worth). I ferment in a fridge with an aquarium controller, making it easy to cold crash in place. As soon as I have 2 empty's I fill them and schedule a brew day. I have found that I can do a quick finishing pale ale for one batch, then a lager that takes much longer as the next and it flows pretty good.