Add beer and gas quick disconnects. And hose clamps.
You can always add secondary regulators down the road, but trying to do it around that manifold would be rather awkward. Easier would be to simply buy a three-body secondary and run a single high-pressure hose to it from your existing primary regulator. Connect your QD drops to the secondaries and you're in business.
That said, most folks end up content without having a regulator per keg, so I'd say go ahead with your gear list, and if you ever decide to go nutty with regulators you can always sell the manifold...