John Freau (I think he went by "Futuret" on the TCML) is still the main if not only manufacturer of readily available spun toroids. Last I saw he was the only eBay seller selling the 4" and 6" major dia. toroids.
Most of the design n stuff is done, kinda just working on sourcing hardware parts for them. Unfortunately all the parts are rather expensive, so I'm not sure I'll be able to handle the initial investment of making a few up. Crowdfunding is a possibility, but I don't want to have myself by the neck if I can't meet deadlines etc.
Well, so far the electronic components (not including the toroid, acrylic for the case etc) are around $100 raw cost. By the time all the hardware is added they'll probably be approaching the $180 mark or so. That's $1800 initial investment if I wanted to make even 10 of them up
It's secondary feedback driven, just using a simple 74HC14, into some gate drivers, usual gate drive transformer, then a pair of IGBTs. The tank consists of 2 2200uF 200V caps in series, and are charged via a small stepup transformer for current limiting/safety. As such the coil runs on 12VAC input and has low BPS rates, but decent streamers