Hi and welcome. I am not a builder so am not going to be able to comment on much of your post. Just a comment and a question from me. Definitely go with chlorine. Don't let anyone talk you into doing Baquacil or any of the mineral type systems. Also, wondering what makes you lean towards a cartridge filter? Just curiosity on my part.

Hopefully one of our builder types will chime in here later today to offer any advice they can.