Yes it is a hot swap bay, and that thermaltake adapter looks great.
I found HP's part and ordered 2
http://www.amazon.com/gp/product/B0...ie=UTF8&psc=1&smid=AO0HFY2PTJS7Rwhich should allow me to put each SSD into the 2 open bays I have, so I thought I would try that first as no wiring.
If I ever need to expand, I bookmarked that adapter.
Thanks