Where to buy a cezve/ibrik?
In downtown Toronto?
Your best bet downtown would be in Greektown along the Danforth, or else some of restaurant supply stores like Nikoloau on Queen West or U-Deal on College.
If you're willing to travel outside of downtown (but still TTC-accessible), Marche Istanbul on Dufferin (between Lawrence and the 401) has them. As do places like Arz on Lawrence west of Warden.