AVRnj, everything came from eBay. There's a guy who's selling the manifolds and they had all the other components I needed, except for the check valve, I got that from another guy. Here are the listings:

Push to Connect Inline Check Valve Union Fitting 6mm OD by Mettleair | eBay

Y Type Quick Push in Pneumatic Connector Adapter 6mm | eBay

Pneumatic Throttling Adjustable 6 Way Oil Distributor Valve Manifold Block | eBay

Brass 3 Ways Adjustable Distributor Manifold Block for 4mm 6mm Tube | eBay

5 Pcs 4mm Push in Pneumatic Valve L Style Connectors Quick Fittings | eBay

http://www.ebay.com/itm/321166071619...84.m1439.l2649

And then the actual pump:

http://www.ebay.com/itm/231163445994...84.m1439.l2649

With shipping, it was $50.45 for the manifolds and fittings, $12.13 for the check valve, and $56.50 for the pump. That's $119, and all I have left is the tubing and mounting hardware. Seems like it could be done for under $150.