I use a variation on Reil's design that a friend came up with, and it works quite nicely for us.
Unfortunately we can't seem to find reducing bells with the right shape anymore, but melting metal in a home foundry, backyard metalcasting, metal casting has a propane burner design that is naturally aspirated without a reducing bell. It's just a length of pipe with some holes for air intakes, and it looks an awful lot like a crude version of my blowtorch. I'm still waiting till I have the time and the inclination to try it out (I hate drilling in pipe without a drill press, it bugs the bajeebers out of me.)
Our jet was drilled with a #60 bit, but I've heard of people who don't like those little fiddly drill bits drilling a bigger hole and tapping it so they could put in welding tips (never tried it myself.)
Definitely use a regulator, preferrably with an emergency on/off valve. We've got a cheapo red regulator with a gauge on our burner, our hose is the standard stuff you can buy at the hardware store as replacement propane hose for BBQ grills.