I have just phoned Queen Mary, and they only offer a
large hall to
seat 280 as a standard. "The Great Hall" has seating for 600 or more,
but at the moment they cannot offer this as a standard feature of a
package (various issues). The can book for August 2010, and they
should be offer on site accommodation for all (a few minutes walk
from the lecture room). But the prices for 2010 can only be finally
fixed in 2009.
You need to find out more about this Great Hall - without it, the
venue is useless.