That would be a good idea. That hardware cloth is tough stuff. And the pea gravel is great for drainage. We use it in the horse stalls under the bedding and the stalls always stay nice and dry
Oh another thing, if you do a wooden floor it will need to be raised off the ground a few inches, otherwise your wooden floor will rot from the moisture in the ground and youll have to spend the money to replace it every few years
It is doable. First you have to make sure you use heat treated wood not chemical treated. Next you need to make sure you have proper drainage. You could use wooden boards and make sure they are spaced far enough apart to allow water to drain but close enough together that your bedding won't fall...