Cal here from Shopify, thanks for reaching out to us. This is a great question.
Each payment gateway will have its own Acceptable Use Policy which is worth reading in order to be certain your business is compliant. For example, here is the Shopify Payments Acceptable Use Policy, in case you were interested in using this gateway. I'd suggest reaching out to your gateway of choice customer support to query whether your niche of products is supported by their gateway. If you start using a gateway and don't comply with their AUP, you will be at risk of having your funds held by the gateway and being banned from using it.
There is also a comprehensive list of gateways for your region here, which you may find useful if you find that a particular gateway doesn't support your products.
Best of luck!