Koshi Chimes I bought my koshi chimes from various sources. Just google and find the closest retailer. One source worth mentioning is Hokema, they also sell other sound healing instruments like the Sansula:
Koshi Gong Stand This is the official website of the company that builds them - Studio Gong: http://www.gongstands.eu/en
Ebay This is the ebay listing where I bought the gong stand on ebay: https://www.ebay.com/itm/Solider-Buchholz-Koshistander-40-cm-NEU-GSTP-40K-Harmonie-/332022503063?hash=item4d4e155697:g:MtAAAOSwImRYHEy0
DIY You can also use any gong stand and just add the 4 hooks for the koshi. Or start from scratch and build your own - or ask a local carpenter to give you a hand.
There are three kinds of Sansula - Basic, Renaissance and Deluxe. What is the difference?
So, I own a Renaissance Sansula and think it is the best choice for most people. You can order them directly from Hokema https://www.hokema.de/en in a variety of different tunings with a bag and an aditonal tuning hammer. There is a variety of tunings for this instrument and I use Heavenly A.
A little company in Wales, UK sells stunning high quality Shruti boxes. The Shruti Box M1 I play in this video is a small and portable instrument (about 2,6kg) that can be used for yoga, kirtan, or meditative music sessions.
Another source of high quality shruti boxes & a lot more is this company in Berlin: www.india-instruments.com