Its not big enough, its not big enough!!
I'm sure you have thought a lot about this, but as someone who just recently got into kegging - I urge you to reconsider. I have a nice 2 keg system that lives in 1/2 of a standard refrigerator - only room for 2 kegs and a 20 oz CO2 tank. I am already unhappy. You should REALLY, honestly consider if 2 kegs will be enough - and not just based on consumtion rate. I was sure that 2 kegs would be plenty for me as I don't drink that much, but it hasn't taken long (2 batches) to realize it isn't going to work. I think having the space for 3 kegs is more realistic. You will be very limited in only having the space for 2. The space for the third allows for the next brew to be carbing/conditioning, or to have a new keg ready to go as one is dying off or to have a third "choice." I wish I had the space to keep a full time rotation of light+dark+seasonal / special flowing. I find myself agonizing over what to brew next and how to time out the brewing cycle to coincide with available space. I like beer, and 2 choices just isn't enough
Could your drill out a CO2-IN hole and move the tank out of the refridge to get that extra space?
FWIW - Just wanted to add my .12 cents.
and if you haven't purchased the sytem yet - I'll put in a vote for keg connection or keggle brewing.