I think you should reconsider using an automatic watering system. Changing bottles gets old quick. The tubs in the plan you're using are 8 inches tall which is too high for some ASF's to reach water. Take a look at the LARGE size litter pan from Petco.

I built my second rack different from my first and I'm dying to make a third because of the things I want to change from the second.

Good luck.