As John stated, most of the manufacturers only produce 5/4" decking. A few do produce dimensional lumber, but even those manufacturers appear to only have one or a couple of nominal 1" (3/4" actual) sizes. One manufacturer,
Plastic Lumber Products , sells 1" x 6" but no other sizes.
In answer to Tony's question, yep, it comes in black. Here's a link showing colors and sizes of the dimensional lumber from Plastic Lumber,
Colors & Sizes Do a Google search on "plastic lumber" to get lots of manufacturers and distributors.
On last point, if you do use it for bedwood, make sure you have the stock, under-bed heat shield installed. Otherwise you will probably melt a nice hole through the bed.
