I wouldn't rush things for now. I think giving them a few days with just the paws under the door is good.
I waited about a week before I actually let Vlad and Oksana loose in the same room, they were both still wee things. With Maks and Kiska, I didn't have the luxury of having a door on my room like I did in my old place, so I had to use the bamboo screen I use to block them from the front door. Vlad and Oksana were around 9-10 months old, and Maks and Kiska were about 3 or 4 months old. There was a lot of hissing and swatting. I think it did help a little that they could see each other. Of course, with Maks, they sprung him before the week was over.
If Roland is showing interest, maybe it won't take longer than a week or two. I just don't think you should rush it too much. It would be harder if you put them together too soon and they aren't ready and things don't go well. Then you'd have to start all over again.