: We've got Lowes and Home Depot local. Plus, I know there are 1 or 2
: "real" lumber stores in the area. I glanced through some
: "Cedar" that Lowes had, but it was incredibly knotty.

: My goal is to try and find 1x6 12' boards. If I can locate WRC, I'll go with
: that. If I can't, I'll figure out what's next (be it 2x6 and more ripping,
: pine, etc.).

The Lowes stores in my area (Denver) sell clear redwood S4S in 12 footers.
The Sea Bee in the instructions you will be using is made from redwood.
It's lighter weight than pine and has properties similar to cedar.

Tom