Does anyone know the dimensions of the tubing/barbs/anything else I might need to hook up a standard CO2 tank to the ball-lock keg, then to a single tap draft tower?
I think it should be fairly simple to adapt to corny kegs (in fact there is a picture of the fridge filled with corny kegs.)
You have QDs for the kegs, so you have the connectors needed on the keg side. You also need hoses and connectors to connect the keg to the tower and to CO2:
And that's it!
If you have already the parts for the sanke (commercial) keg, but have no plans to use them, then you already have all the parts you need. You can then just cut off the keg coupler at the hose, and fix this to your beer QD, and do the same for the gas line.