FWIW, I've managed to make both 3-monitor and head-tracking work on my system, on the cheap. As someone previously posted, it is a huge leap in the immersion factor. Coupled with head-tracking it will give you quite a feeling of "being there." It will change how you see the game, both literally and figuratively.
3 monitors will help with your SA a bit, since there will be fewer view-switches you'll make. What happens, as you've seen in the screenshots others posted, is that your monitors will encompass a greater swath of the horizontal field of view. However the view is proportionately shorter, so you will still be doing the same amount of Up-viewing as before.
I've recently begun using the 3 panels in combo with head-tracking and really, it's an amazing shift in how I perceive the game. Now I feel much more like I'm IN a cockpit, and thanks to the head-tracking, my head position is independent of the orientation of the aircraft, as if I were compensating for banks and rolls.
The downside is that you will have to relearn gunnery a bit, and your SA will suffer as you get used to tracking targets with your eyes and not your hatswitch.
I used a freeware utility called SoftTH to link up my 3 dissimilar monitors (like a charm). For head-tracking, I used a free, semi-DIY solution called FreeTrack (works great). You can google both of those for their websites. Maybe I've been lucky, but I got both of these things to work fairly easily, though fine-tuning the head-tracking settings is an artform onto itself.
Good luck
