I fitted an EVA stove for my mum a couple of months ago. All was fine at first then then after a couple of weeks the thing started to smoke. To cut a long story short, I had to remove the baffle plate just below the flu pipe and make the air holes bigger in the stove top plate, after that it was fine.
The thing was that resticted that as soon as you got even a very light build up of soot it wouldn't burn / draw.
I'd also ignore the whole, what size for my room thing. Fit the biggest one you can (obviously it still has to look right) the output figures for all stoves are maximums. It won't be running at full that often, most of the time you'll find you're nearer half the stated output.
I'm not saying don't buy an EVA, it's very solid and well built but you might want to modify a few things before you fit it.
Stuart