not trying to piss on your parade Hoser, but i don't understand how this would work functionally. The temperature you are likely to want as a fermentation fridge will be too warm to be a suitable keg fridge. Conversely, the temp you want to dispense a keg at, will most likely be too cold to ferment at, even if you only brew lagers....This obviously means that for the two or so weeks that you are fermenting, you can't drink your beer, and whilst you drink your beer, you can't make more...
I didn't realise you were kegging. Most (probably all) brewers that keg and have fermentation temp control, will have separate options for both fermenting and keg dispensing. I have three (which is probably very common). I have a big fridge that fits two fermenters side by side for fermenting (obviously...) i have another fridge which is half the width that i keep my bottled stock on one shelf and a keg conditioning underneath them, and then i have a chest freezer for dispensing my kegged beer. The only problem is i have three fermenters which means at the moment, two are in the big fridge set to 17 degrees, and the other one is sitting in a bath of cold water trying to stay under 20 in this hot weather...
cheers,
Nath