You'll want them to make sure you get the right size too, and locate it properly. I got a heat pump a few years ago through a good firm, but it turns out it's not big enough - on cold nights it barely stopped running, and heat pumps that are working hard use more power than larger units that are working moderately. I put in a bigger one and moved that one to my kitchen, the new one seems much better.
If you're trying to heat a whole house with a single heat pump then 11kw will be about right, maybe a little small. You might actually need to 6-8kw heat pumps to cover the whole area, or you might look into a ducted system like the Fujitsu sleep pump, which is what I should've done.
I just had a heat pump for an area that I guess is around 60 square meters put in, a moderate sized lounge, wide hallway, and three decent sized bedrooms (that doesn't count the separate kitchen/dining area) I got the largest Fujitsu Nocria unit, 8kw minimum, 11kw peak. It works well, though it's a little loud, the indoor unit has a fan that could just move air around a huge area. On ultra quiet it's still not super quiet, but it's not awful either. My older Daikin is a bit quieter, I think, but pretty similar. Overall I guess I recommend the Nocria, plus Consumer rates them very highly. I paid $3400 which includes some kind of government subsidy, I think it was around $4000 without.