I looked into it. The cost was more than I thought it would be after you put all the pieces together. Also, if you are on a budget, you won't have much room for error if you don't get the end result you are wanting. The look and quality of the enclosure may not be what you are envisioning. In the end, I wound up going a different route due to time constraints/budget. I bought some Kicker KMT6's and I have been pleased. They aren't on the level of the HLCD Pro Audio stuff, but they are better than cans. It was a nice compromise for me.
As far as resources, I searched the site for info and there are also some good write ups on http://www.bierbower.net/diytower/home.htm
If I am not mistaken, the Eminence stuff is paper cones and there is a coating you buy to spray on them.