well, i personally haven't any experience with this, but i always believed that angels should be kept one per tank. I looked online at a compatibility chart, and it said that large angels are able to be kept with other large angels, but with caution.
Some info on the queen angel:
With the potential of reaching an impressive 18 inches, the Queen Angelfish needs a large tank — at a minimum of 150 gallons, with lots of hiding places and live rock for grazing. Not a good reef dweller, the Queen Angelfish is prone to nip at stony and soft corals (sessile invertebrates) and clam mantles. It can be aggressive, so it must be introduced to the community tank last. A somewhat difficult angelfish to keep, Queen Angelfish often suffer from incorrect water parameters and diet.
Some info on the Emporer angel (aka the imperator angel):
The Emperor Anglefish requires a 100 gallon or larger tank with live rock for grazing and hiding. It will nip at stony and soft corals (sessile invertebrates) and clam mantles, but may be kept with small-polyped stony corals and somewhat noxious soft corals.
Sounds like the queen may be difficult to keep. Since she requires a 150 gallon, having a 180 is ok for her, but i personally wouldn't combine the two... Maybe if you had a bigger tank, like a 280, it might be a little more plausible, because the queen will have her 150, and the emporer will have his 100, and there will be a little room to spare.
You also might want to try posting this in the agressive forum... You may get a better response...