This store is the best and they have a very reasonable priced selection of wood as well as all the brackets and stuff you could even need.
They are by far the most helpful and friendly hardware store I have been to in the downtown core and I have been to them all many, many times.

This is a handy little local hardware store that has much of what is required by people living in downtown Toronto. I have purchased all of my spring garden supplies from this store and have also bought bike locks, paint brushes and lumber. The owners are always more than helpful and will even recommend other nearby stores at which you can obtain supplies which CAAM do not carry.

A downtown hardware store open on Sunday! In kensington market/Chinatown - has almost all the hardware you could ask for and keeps Chinatown hours. Helpful - almost alway had what I was looking for and did I say that it was open on Sunday?