Hey WBS,
The ring stands and burette clamps I got from Amazon. Just use their search engine and type in "Ring Stands" for the stands, and then "burette clamps" for the clamps. There are many different ones available. Make sure the ones you are interested in, that you check the dimensions for the one(s) that suit your need. My stands go 22" high and the bases are solid metal and can totally support 3 big hosts with great stability. The clamps I have open up wide enough to hold your 473 frost, a Dragon Lasers 532 100mw Hulk, the PL series from Laserbtb (all pretty big hosts) , and can be closed to hold a laser pen. The stands and clamps are two of the best investments I have made for my photography of lasers.
The idea of doing this was LPM member Marco Polo's idea and it is such a good way to mount the lasers. They are in a fixed position with zero chance of moving (as long as the adjustments are done correctly). And as you can see I use them almost every time I photograph hand helds in all different configurations