This True Union Ball Valve would be perfect for the skimmer and return. It provides a nice ball valve and a quick disconnect for about 25.00 each.

http://www.intheswim.com/Pool-Equipm...on-Ball-Valve/

A standard union between pump and filter would do the job.

Back in my early days we used brass valves and the hacksaw disconnect. Most of our installs were with the factory flex hose so we never got too carried away with plumbing, plus in Arizona the pools were left up and running year round.

I provided labor only letting the different pool stores sell what ever they wanted, or could, to their customers. What they sold is what we installed. They slice valves became very popular later on, many of the filter kits even included them. Never had a problem with them.