29ers are VERY popular here in the mid-Atlantic region. It seems every other rider has one.
That said, if they're not common near you, you might want to stick to 26" wheels for easy tire/tube/rim availability. Also, 29er wheels aren't quite as strong as 26". They're strong enough, but if you're rough on gear, the average 26" wheel is a bit stronger than the average 29" wheel. That's a generalization, but something to consider. FWIW, I ride a 650b rigid singlespeed (was previously 26") and have started accumulating parts for a geared (1x9 speed), but fully rigid 29er (this will be bike #4!).
Also, it is better to get a good hardtail rather than a poor or mediocre FS bike. Not only will it function better, it will last longer.
I'm not fully up to speed with the different marketing classifications such as "All Mountain" since I build my own bikes, but I understand it to mean a bike a bit more flexible in purpose than either a cross-country or downhill rig. They tend to be in between the other two in capability, but not quite perfect for either. Unless your trails are very technical, rocky, rooted, etc and fast or steep, you might be better off with a good X-country bike. Very little here in the Mid-Atlantic region really dictates a dedicated AM bike. Most of downhillers use AM bikes as their general purpose rigs, but XC bikes still outnumber the AM bikes. Personally, I prefer faster handling, more nimble bikes and what I've read/heard indicates AM bikes don't quite fit this because of their need to be more useful on downhill terrain. I could be wrong, but that is my perception.
Chris