Build an Online Store Revisited

I'm looking for someone highly skilled with WP, woo commerce and the Google shopping plug in for Woo too. I have an existing WP template-based site that works fine as an on-line product catalogue but just hasn't been selling as required. We did have a very basic cart but it didn't offer anywhere near the customisation we were looking for and was 'clunky' to say the least. Having already tried to get this work done on here before we're proceeding with caution as someone took $50 up front and did jack shit for it and then gave every excuse not to complete the work agreed. As I understand it the existing version of WP/plug ins need updating and there's a virus/malware from a previous hack on the host which needs resetting once the site is sorted. Having spoken to a developer friend it seems like integrating woo commerce within a non woo theme could be a pain in the arse for getting my site to work across various screen sizes? If someone can keep the look and feel of existing template and has access to a woo theme that will do everything I want and be less problematic to set up with the Google shopping plug in there might be an argument for migrating all the existing info across. If someone is suitably well versed in Woo Commerce to just add it to existing WP template with the Google Shopping plug in working as it should we're happy to go with the best option. There are other small jobs like fixing videos, getting twitter feed to work and incorporating our instagram feed to a photo gallery. We know that this should be very simple for someone skilled so we're not looking to blow the bank! We don't have an exhaustive amount of products so we're looking for a fast turn around so you must be able to turn the project round ASAP.