Magento Category Page and Product Page Design

Redesign of category page layout and product page layout required. The CSS side of it is not so much of an issue as the actual framework that creates the page itself.

This is roughly what we are aiming at:-
https://www.matchesfashion.com/products/Audrey-Louise-Reynolds-Zip-through-cotton-hooded-sweatshirt-1238306

There are specific elements that are important: -
1. showing stock statuses on individual size options
2. the concertina type tabs (description, size and fit, care instructions, provenance)
3. a size chart that has default charts AND a custom set of attributes for each product

Products will only have size as an option, although there is potential for some to have a further customisation options in the future.

Category page based on same site
https://www.matchesfashion.com/mens/shop/clothing/t-shirts

Important requirements: -
1. ability to have custom messages under products (eg out of stock, new, sale)
2. change number of columns on display, or show as one per row
3. ajax based navigation (if this needs to be purchased from a third party this will be additional to the budget)

Again, CSS not as much of an issue as structure for this page too.

There are numerous other elements to this site so I am looking for a good working relationship. Please note that our company specifically supports small businesses in the UK and therefore UK based freelancers will get priority (cost obviously being a factor).

Note: I removed the “budget” from the project as all the bids were simply for that amount. I do not know whether the project should cost £2 or £200 so I would like to receive bids of all levels to gauge how much the project is actually worth.