Process of ordering a fireplace

We're in the process of ordering a fireplace to our holiday apartment. We've just started to build the apartment, so thought it might be a good idea to get the fireplace in at already in the building stage. The builders said it is better and often cheaper, but they asked where I'd be getting it. I have been contemplating Uunisepät, as I would get a guy to fix it in for us as well so I don't need to hire anyone separately. They have some ok fireplaces, but does anyone have any experiences with them?

I was reading on some forum that people had been complaining about their service, but I could find similar threads on other suppliers as well. At least Uunisepät has a relatively wide selection of the fireplaces, and they fill the CE standards as well. This is important to me, if we get the fireplace in the building stage I don't want to have the regulations changing on us and us needing to replace the fireplace with something else. As this is the first thing we build from the scratch I'll rather be overly cautious than having to spend a lot of money later.

So anyone have any experiences with Uunisepät? Also I'd like to hear if you know how the other fireplace suppliers are, my mind is not yet set on Uunisepät to be honest. I just haven't come across the perfect fireplace for me. Yeah sure, there is some quite decent ones, but none of them is like the really perfect one so far. But I'll have to keep on looking! Any tips and experiences you have I'd love to hear about them. I am sure I am not paying attention to the right things anyway.

Oh one more thing, Uunisepät is saying they use olivine stone. How does this differer from other stones in look and use? I mean they write on the webpage that the fireplaces are more durable and easier to clean etc because of the material they're made of, but if you'd have any personal experiences let me know! You know, companies would speak only good of their products anyway, heh. Thanks!