Hello Ingy!
What do you think of adding a fireplace mantel cast in stone? This material is more affordable than natural stone and can be molded to suit your needs! The mantle can also be adapted and customised to any type of fireplace (like you gas insert!).

Here you can see our pre-designed and custom if you want to get Inspired! >> http://www.omegamantels.com/omega-mantels.php

Thanks - the existing shelf is just an Ikea floating one which we would like to replace too.

Also would appreciate input on whether to stop the stacked stone cladding where the stripes end now or continue onto the entire wall. Thoughts?

we did the wall and the shelve

www.dracmerealstone.com many choice of stone

That's a gorgeous fireplace - thanks! Very inspiring.

I just saw a contractor installing stone on a big box store's exterior. It is a click-together system and he likes using it. I wonder if you could do it too. He told me it's called BeOn Stone. I would like to know more about it myself because we need to repair some brick areas on our home and the company's video looks very intriguing....
Has anyone used this type of system?