One word of warning - since you're not using a regulator for each keg, you will need to do the following when you add a keg if they are quite full, even with a gas-in short stem:
1) Shut off all 8 valves
2) Put new keg in place, burp the keg down to almost 0 PSI
3) Attach new keg to gas line
4) Turn on gas line on new keg, and let it pressurize
5) Reopen the other 7 valves.
HTSC
Each of the shutoffs on both manifolds have built-in check valves, so this isn't an issue for me, thankfully. On my last four-tap kegerator, I was using the same manifold with no issues.
Thanks for the advice though. Great advice if the manifold doesn't have check valves, or there aren't check valves installed in-line.