Show 1 or 2 sets of custom fields in checkout process

-- HikaShop version -- : 4.0.1
-- Joomla version -- : 3.9.1
-- PHP version -- : 7.2.12
-- Browser(s) name and version -- : Chrome 71.0.3578.80

Hi there!

We sell holidays via our Hikashop webshop (still under construction).
A holiday is in fact a Hikashop product, the product price is the per person price.
Visitors can book a holiday (buy a product) and they can choose an amount of 1 or 2 of the same product. This way he can book for 1 or 2 persons.

What we need:
If someone buys 1 product (eg a holiday for 1 person) we need a set of (custom?) form fields to appear during the checkout process. The buyer needs to fill out his name, date of birth, address and contact info.

If someone buys 2 instances of the same product then we need 2 of the same sets of fields to appear, so the buyer then can fill out the personal info for 2 different individuals.

I think we should be able to achieve this with aid of the custom forms, but not sure if this can be done.

Would really appreciate if you can share your thoughts on this!

Thanks,
maurice