You may want to check out the Grand Olympia in Stoney Creek. Friends of ours got married there in July at their outdoor site, and it was really lovely. They have an indoor chapel as well, if it rains. The only thing is that you'd need to book your reception with them as well.
If you don't have your hall booked yet check out Carmen's. They have an outdoor location and they also can convert one room for an inside ceremony. Just like Grand Olympia you would have to book the reception with them. Talk to P.J. Mercanti if you are going to call there. I found he was the best to deal with. You can also look into Royal Botanical Gardens. Not sure how their fee's work.
Hi, There are two beautiful locations in Hamilton that come to mind. The first being the Ancaster Old Mill and the second is Liuna Gardens in Stoney Creek. Both offer beautiful outdoor ceremony and photo locations with nice indoor backups.