Domes
Thanks.
My response was short and snarky. The full answer: you'll have to get your hands on 45 domes. This is a small market. Sometimes you can buy domes off someone. Usually, or what I have done in the past, is buy a second board or BKE Redux domes. Lucky for you, IMO, 45g are more common and 55g rf domes are pretty sought after. You could potentially trade with someone. I'd start with posting to the classifieds to see if anyone wants to trade or sell theirs.
Edit: Like HotRoderX said, it's not easy to find stock domes. BKE Redux domes are a good alternative. That being said, I'm sure a lot of people switching to BKE will have their stock domes lying around, so now might actually be a good time to trade.