The 5L minikegs have apparently gone out of style for some reason. Yes, they are reusable; I've had good success with them. I like them because they're so portable! I also like your minikegerator idea, though it kinda takes portablility out of the equation.
Looking at the online suppliers, I can't find taps at the moment, though. Look here for alternatives.
Beer-Wine.com lists 5L mini kegs with built-in taps, which solve the tap problem. Alternately, you could buy imported beer in 5L minikegs, drink the beer, and keep the keg. In most cases, the minikeg with beer in is only about $20, where a new, unused minikeg at about $10.
Here are some good tips on dealing with 5L minikegs.
I'm sure someone (or many someones) will list all the reasons why you shouldn't even consider 5L minikegs. But they work for me!
I've seen those as well, but for the money, I'd go with a bucket of ice. No, the ice won't keep your mini cold for days, but those things are so small, if I needed to keep one cold for days, I'd put it in the fridge. For gatherings, the ice bucket is far cheaper, and less likely to malfunction.
You could put the $$ savings to go use in equipment or ingredients.