Help with single product page

Hello there,

I need some help with my single product page. I have attached a link to one of my products (however the issues persists throughout all of the product pages). Basically the images look weird as they are all different sizes and the wider images look really small and stays at the top of the image box. I was wondering, how can I make the images have dynamic sizing/dimensions? Or even centre the images so that the wide images are at least centred and not at the top (leaving a large blank gap underneath). I am open to any other recommendations, however I cannot change the size of every image as it is very time consuming and some of the images NEED to be that size.

I am also wanting to change the “expand/popup/zoom” icon. At the moment it is a square icon at the bottom right and is grey in color. I want to change it to a magnifying glass and white color instead.

Thank you!

The page I need help with: [log in to see the link]