Hey Mark! As like you i am a newbie to the forums but ive picked up a few things. The majority of us here will tell you that we do not promote two beardies living together in the same enclosure due to the fact they like being alone, and are much happier this way. As to the tank size, there really isnt a maximum size Tank. That being said youll need to be making sure that you are monitoring the tank with thermometers. i would get 3 of them. one for warm side, one for the cool side, and one in between. With the tank being this large you might want to think about placing a light in the middle that isnt as high power as the warm side, so that it can cause a nice temperature gradient throughout the tank. Make sure you are providing the right basking temps, our Caresheet was super helpful to me! It will let you know about tank temperatures. As i said im new to Dragon keeping but not reptiles. if any one of our site monitors or experts has something to add to this, they probably can offer more

. I hope this info helped, post pics when your done! it sounds like its going to be a nice spacious place!