Flip flop

Well today after months of wanting another bun ( I have 3, 2 outdoor and 1 in the kitchen ) I went to our local rescue center ( oh how I could have come home with all of them, I have tears in my eyes just thinking about them all ) and if the home check on Friday is ok I will have a Flip Flop, he is a male angora bun, never had a long haired one before, apparently he loves being brushed so that will be no problem, he seems friendly and was happy to be stroked and picked up and is so cute. He will live in the kitchen with my little girl, he was a house bun so that wont be a problem, as Cottontop has full run of the kitchen my plan is to put a run in there so they can see and nose each other but not get to each other properly at first, how long would you say would be a good time before letting them get together properly, have bonded my outside buns so know what to do but as the one bun I bonded outside was a baby at first I kept them apart for quite a while till she was quite big and just had wire between them and all was then fine but these are grown up ones, my indoor bun is a very relaxed girl so I am hoping it wont be long, any tips would be great.