Let me see if ive got this right...you are currently running a 3 ring set up and want to switch to 2?
Theres 2 ways you can do this.
First one is you can buy aftermarket chainring (ta do some nice ones), however you may have chainstay clearance probs running such a big granny ring. But you may be lucky, unfortunately its going to be one of those suck it and see moments. Unfortunately sram dont make chainrings to fit your cranks that have the ratios you want. A standard 3 ring crank runs pcds of 64 & 104, where as srams double cranks run about an 88mm pcd so they wont fit. This leads me on to the second suggestion...
Simpliest way round this is to sell your current crankset and buy a specific 2 ring set up. Unless you go for a stupidly expensive set of cranks you should be more in pocket than what you would have been buying new chainrings (if you take away what you sell your current ones for). You shouldnt need to chain your front mech, only adjest the limit screws. I run a 970 xtr (3-speed) front mech on a specific double rng set up (not converted from a 3 ring) so i know it can be done and works.
Well i hope that helps