Mark, I think that you should just build a correctly sized box out of plywood under the box spring, paint it and then, when you have the time to make a nice bed do so. Once you build a quicky bed, like you are taking about, you WILL be stuck with it for all time, trust me on this.
The quicky bed can just be a good stout plywood box, painted, the good bed can come later, when the maple is dry and your shop is more up to the task.
Just my two yen's worth
The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
William Arthur Ward