I'm with
@mickle on the sizing thing.
@superdon , it looks like you have shortish legs, and the 29er frame has to slope upwards to accommodate the wheel size. That said, I would suggest someone of your height and stature should be on a smaller frame, but with better top tube proportions. A longer stem will make that bike vague in the steering.
If you are determined to buy yourself a mountainbike be very honest with yourself. If you are going to commute on it or ride it along simple trails, then you would benefit from a more stretched out, less upright position. If this isthe case, get yourself a cross trail type bike, not an MTB. If you do intend to ride off road, then my advice would be to go to a smaller frame. Smaller frames are more playful, easier to throw around. My lad rode a 16" framed hardtail from 5'8" to 5'11". My Soul is a 17.5" and I'm 5'11" with long legs. The bikes are a bit cramped for day long epics, but perfect for chucking around.
As for the 29 debate? Meh, I think they look awful, and have to rethink the entire geometry of MTBing. The larger wheels and subsequently larger fork legs, stays and so on add heft to a bike which will simply not benefit an inexperienced rider. More experienced riders on much more expensive machines may benefit, but 14.3 kg for an entry level hardtail is hardly a step,forward in terms of evolution. In fact it's criminal.
And anyway, 29 inch wheels are a passing fad. The majority of current bikes are embracing the wonder standard of 650b. This means they don't have to go to the extremes of re engineering all their frames, 650b bikes tend to look better than 29ers, and current market looks like its here to stay. Whether that's a good thing or not is a question others will have to answer. I have no intention of straying from 26". However, take that Bizango back, and have a good look at the Boardman Comp hardtail. Join CTC and you'll get 10% off the £650 price tag. And I think it will fit you better.