Shopify Order Sold Out Items

We are looking for a Shopify developer to make some small changes to our templates to do one of the following: 1) Order sold out items at end of collection: We would like to order any sold out items at the end of the collection/on the last page of the collection. Currently sold out items are ordered throughout the collection pages. or 2) Hide all sold out items: We would also be happy to simply hide all sold out items. We have managed to do this previously, however if it hides a sold out item from a page it leaves blank areas on each page, rather than moving other products to fill those areas. We are happy with either option for this project, whichever you can recommend. Our client only has a small budget unfortunately, so if this is not achievable please let us know.