Well....you are in danger of some feedback that will likely be in direct opposition to your plans.
But to give you a best case scenario, I'd suggest building a 4x2x2 cage so that you don't find yourself in need of an upgrade down the road. Provide more than one basking area to help mitigate territorial disputes, and more than one hiding area. Set it up as a "your half, my half" kind of setup. More important than the size of the cage just be ready for the possibility that they may become a danger to each other as they grow. Dominance is a real issue and one can injure or even kill the other. This is especially dangerous with two males. You may have no problems at all. Its your decision and I respect it. I have had issues with pairing dragons and I have had great tank mates with no problems ever.