GSPAV website project

Creation of non-profit religious website based on 1) Subscriptions - WooCommerce based with restricted pages, current database of about 400 subscribers; 2) online bookstore - again WooCommerce. Main issue I'm having right now is to create a template that has 2 parallel columns (Latin and English) with ability to copy and paste large chunks from one page to another, and ability to search and replace text over multiple pages. Website already under development, but need advice on how best to make it all work. Website is gspav.org.