Shutoff valves?

if interfacing is some sophisticated way of connecting to, then you just screw on the desired barbs... ball valves dont really have restriction? it is a ball with a hole in it so when you turn it the hole moves to the side and blocks water.

This is a 3/4" PVC "T" in this pic on the right, I use it as a drain line on my TEC bench(Not as a in-line). Like OC was saying just get some PVC ball valves at the hardware store and use those. Get the threaded ones and you can screw whatever size barbs you want to in it. Get the barbs there so you'll know they fit,there not G-1/4 and all that there NPTx barb size. They should have plastic or metal either one.

I'd get the valve in 5/8" then use 1/2" barbs and it wont be as restrictive. There $3-4 the last time I bought any and a $1 or so a barb, for plastic ones anyway.

That is how you do it.