VAT switch possibility

Hi,

Not really. You could potentially have two sets of menu items and modules with their "taxed price" setting configured differently and restricted to different user groups and then configure the "User group on registration" setting in the HikaShop configuration to have a different user group assigned to the user during the registration based on what they select in a custom user field.
That way, based on whether the customer selected that he is a company or an individual you could have the menu items / modules with or without taxes.
However, this doesn't address the product page or the checkout since they use the "show taxed price" setting in the HikaShop configuration and you can't set that setting diffferently based on the user group.
So in the end, the only complete solution would be the development of a plugin to override the "show taxed price" setting dynamically based on either the user group of the user, or based on a flag in the session, set by a switch displayed by a module or something.
So you're looking at several days of development for a normal PHP developer. It won't be cheap.

A simpler solution would be to have a "pro" website and an "individual" website so that you could configure the taxes settings differently on each website. I know that LDLC in France does that with www.ldlc.com/ and www.ldlc-pro.com/
They sell roughly the same stuff but the prices on the pro website are without taxes while the prices on the main website are with taxes. But this might not be a practical solution in your case.