Its a tough choice picking a bike in that price range, because there are some really great bikes. The only real way to know which bike is going to be best is if he can get a ride on them, but i know that's not always the easiest thing to organise. But in my opinion the Kona is a great base, is has a solid frame, and most of the components are pretty tough, although some lack some of the strength, because of the budget (i.e. rear mech). Having never ridden the Scott i cannot comment on it as such, but i know that they are highly recommended. Personally i ride a 24Seven, and i love it to pieces, admittedly mine cost quite a bit more than your budget, but the frame is brilliant. If you are open to the idea of "building" a bike, whether by yourself or a local bike shop. Then i would recommend it. 24Sevens ebay shop has a great frame and crank deal, Link. If you went with a rigid setup you could quite happily build a bike within that budget, but a suspension fork would push it above. The advantage of this is that you tend to build a bike that last longer in the long run, but it does mean paying a premium. So to round it up, try and get a go on the bikes, as it is all personal preference really. If for the mean time you don't think the levels of abuse will be too high than a standard shop build will be perfect. But if you do remain open to the idea of building a bike, then shop around because you can often get some great deals on last years models, same as the bikes. Like this norco Link