Product Variations

Hello,
i am looking for an extension that implements product variations and grouping.
I use Journal 3 with OC3 and my requirements are:

1. Different URL (product id) for each product variation
2. Different image gallery for each product variation
3. In Catalog page i want to have the option to group all variants under 1 product
4. Optionally i would like to load the product page with ajax (in order not to reload the whole page when choosing a product variation)

I have already found an extension (product series) that seems to meet some of these requirements but the seller doesn't respond to my question so i hesitate to buy it.

Thank you