Buck Algonquin has these, on page 15 or 16 of their PDF catalog. It's about a thousand pages of good stuff, and it takes a while to download. I think it probably costs about the same as the Groco shown here, which is a $300 piece of hardware.
http://www.fortune3.com/dms/Strainers-GROCO_STRAINER_SEACOCK_COMBO-.html
If you have the experience you mentioned, it should be a piece of cake, except for the standing-on-your-head part of the work.
Regards, good luck,
Tom