For brunch, especially for a tired Bachelor Party bunch, you might just want to consider "Eggspectation", with a couple of locations in downtown and the old town. The one at de Maisonneuve and Montagne will probably be your best bet unless you're staying way up the Plateau. Yes, it's a chain, but they don't mess up your basic brunch selections, have a big enough floor plan to deal with your party, and have a large bar selection for hair o'the dog. Reasonable, as well.
For dinners, La Sila on Rue St. Denis used to be very reliable Italian with a good wine list and the capacity for groups.....unfortunately haven't been in a few years and I heard they changed hands, so a little investigating might be in order.
Also, you may want to try a trio of restaurants owned by the same group - Primadonna, Med Grill, and Sofia, all located on "The Main"/Rue St. Laurent and all on OpenTable.com reservations system, I think. They're presented as trendy/hip, with often something-for-everyone menus (Primadonna is Italian&Sushi!?!) and I KNOW they can handle groups, because some of the Formula One teams have group dinners there during the Canadian Grand Prix in June. Of course, don't know if the "scenery" (beautiful young ladies) is as good when the F1 drivers aren't there!