What level of skill should be need to make and/or play these? Do you want rhythm or melody instruments?

I've make pan flutes from bamboo and acrylic, transverse flutes from bamboo and acrylic, and "xylophones" from conduit (available at any hardware store) all of which are pretty easy to make from simple tools. The flutes are a bit harder to play.

I've also made a tongue drum and a zither, either of which is a bit more work to make (uses power woodworking tools), but fairly easy to play.

I can supply picture how-to picture series for the flutes or xylophone, and instructions for any of them.