Whatever brand you choose, avoid smuggled or 'Cargo' stock. One of the ways you can spot them is by inspecting the sidewall. It should be uniform and not bent in any shape or form.
I would recommend you to only go via a authorized dealer, regardless of the brand you choose. I usually go for Michelins and bought them last year from Corner Tyres (one of the few shops who carry legally imported michelins in the twin cities) in saddar. If you're looking for yokohama, go with ZAMS Peshawar Road.