Intake/livewell questions

[hobson]

On my 20' I plan on putting a 20 or 30 gallon livewell underneath the leaning post. I also am building a box similar to a 23' across the raised and enclosed transom. In the corners I will have two small livewells, something like 3 gallons each. I also plan on mounting a raw water washdown system. Now my question is if I have a water pickup beneath my leaning post for the large livewell, will I also be able to use the same water pickup for the two small pitch wells in the back and a washdown system? I guess I could always put another pickup back near the transom for the washdown and two small pitch wells. The less holes and complications the better. Any help or ideas would be appreciated.