Victoria still have few chain hotels, but Fairmont, Delta, Marriott are represented, along with a lot of more budget concious chains like Best Western, Ramada, Holiday Inn, etc
Please note that a lot of the lower priced properties are along the Douglas St area which is probably not where you would want to have your group stay.
I vote for hotels near the Inner Harbour, or like the previous poster, in the area of the Parliament Buildings.
So long as your dates are not over Valentine's or President's Day weekend, you should be able to get a good rate. Are you going to have 4/room? Usually hotels will negotiate group rates for 10 or more rooms, so that's something to consider.
Re Vancouver Airport hotels - again, lots of choice. The budget type chains are mostly near Bridgeport Road area, which is not in the 'heart' of Richmond. The Marriott, Hilton, Richmond Inn, and one of the Ramadas and Quality Inns are right in the heart of Richmond, and a 5-10 minute shuttle ride to the airport. The Fairmont is right inside the terminal, but winter is their peak season so rates are high. The Delta is the next closest, and you may find favourable rates there, but it too is not in the heart of the city (ie not close to shopping, etc but if it's the last night, that probably won't be a concern)
Please let me know if I can help - I am not often on the boards anymore but will keep an eye out for you if you like!