change order confirmation email - zen cart

I'm middle of design website with Zen Cart. There are two thing I need to modify files. 1.I need to change order confirmation email description that confirmation email should be automatically send to store owner and customer. I want to keep all page description, but modify layout with table. 2. I need to add a function that customer can add one more specific item in to shopping cart from "Step 1 of 3 - check out" page. that means add one nore product during the check out (1 to 3) processing page. I need this done by 3-4days.