Duckboys,
Give it time buddy!! My woodies havnt started laying yet either, but they are checking out the boxes pretty hard now. My wood duck project on the wild woodies havnt produced any eggs yet either, they usually dont start laying until about the end of April around here. Your in Colorado, they might be waiting for temps to warm up a bit. As far as the breeding, you might be missing it, it only lasts for a few seconds. As long as they have a good diet and access to enough water to swim/mate in, you will be fine.
As far as the boxes go, you could have saved yourself a ton of money by building your own, you can build three nest boxes for about $21. One sheet of plywood and a box of screws.
You can get the plans off the California Waterfowl Association website. Look under the wood duck project and the plans will be there.
Goodluck!.............Jason