Phone to order products

We have 1 manufacture who will only allow us to sell their products over the phone.

What I need is to either somehow force the checkout to only use the phone order payment option if one of the brand products is included in the basket (I know this could get messy if they have other items in their basket) or what would be probably easier would be to somehow change the templates to replace the “add to basket” button with something like “call to order” for this brand, like a simple

if(brand = x) then

call to order button


add to basket button

Any help/advice would be appreciated.


OK so I found this link which looks like it does exactly what I need it to.