Opencart Online Store Updating

I have an Opencart website that wants updating the site is running version 2.1.0.1. Some modules need updating like ajax checkout to make checkout and other features easier. Also images have become varied sizes and want good standard images across site. SEO add on not working great so some advice on optimising for best SEO and analytics [login to view URL] © 2009-2017 All Rights Reserved. Version 2.1.0.1 Pav fotostore THEME is used. A Freelancer who is familiar with this theme and opencart will find this project of interest. The key objectives are update the website and make it very easy for customers to use. This will mean changing some of the menu and header / footer details.