I've used climate panels on jobs as well, and it's a slick, but very expensive system. They even have proprietary caulking with aluminum in it that goes in the grooves before the tubing.
http://www.viega.net/productcatalog.html#model-group284639617504Lots of people in my area make their own climate panels by ripping 1/2" ply to 6" strips. I think you can even buy the rounded corners, but you can also just route them in situ. The tubing is typically 5/16 or 3/8". My recommendation would be (from bottom up): framing, subfloor of your choice, 1/2" tubing panels, and finish floor. You need to keep the tubing pretty close to the finish floor for the system to be effective. The finish floor shouldn't matter, as long as it's really well acclimatized.
