Build feature for my website

Hi there. I am developing a shopify website whereby I want my consumers to customise their product. I want them to be able to upload images / text and then have it show up on the image (mock-up). I then also need options for purchase such as MOQs (Minimum order quantities). I then need the design file to be exported as a design ready file. I have some websites for examples that do this well. I also want it to match with the design with my website theme (Wokiee). The feature also needs to be quick and scalable over all my products. Thanks.