@Rakesh: I think we have another solution: that you can set template for all K2 item in a category.
Do you know we can set template for all K2 item in K2 Category config?

Not sure what you mean, do you have a demo of it somewhere?

Really just need to have the item open in a Modal/popup window. Just like the BT K2 module does.

Any quick fix possible?

@Rakesh: I mean you can create a menu to a category of K2, then you can assign menu to show/hide on the K2 item details page.
This module don't have function to show item details in Modal/popup window.
But, if you want, we can help you custom module to add this function as custom server.
You can submit a ticket here: tickets.vinagecko.com/ Our support team will help you with small fee.

Thanks, guess I will have to do without the modal window, there is no budget for it.