Ride in northern Maine, Caribou north,west, 2-300 mile days, fast trail riding and occasional ungroomed logging roads, and have a fun habit to play in places the 1200 shouldn't go.
Well for sure you want to mount some carbide bars on the outside. Just about anything will work there as they are more preventing ski wear and a little for darting prevention. Shims are a good thing for bar wear and darting prevention. Easy to make. Recommend you replace the rubber at the same time.
For the center bar you have to consider that the more bit you have the harder it will be on your arms for a 300 mile day. For a good bit, I found the Shapers work well but I won't use them as they wear me out too fast. A good round bar with a lot of carbide will turn easier. Jim Jamison has been using a bar from Qualiport ?? Its a round bar with a bulbous head on it. I have good success with shaper duce bars on my sleds. Both Jim and I use 6.9 on 1200's however Jim has moved on to 900T's. Being your going off trail some, I'd stay away from snow trackers