The Zulfiqhar is based heavily on the M-60 (which the Iranians have) and looks quite a lot like the M1A1. It has a 125mm gun and a couple of MGs. It isn't going to be the equal of MBTs like the Challenger II, but bear in mind when Iran were designing it they still had Saddam to worry about, and it was easily the equal of anything he still had. Irans other major enemy was the Taliban, and they didn't have tanks at all.
Other tanks the MEA can use are the Challenger I and II, the M1A1, the M-60, the T-72, T-64, T-55, T-90 and T-95, the AMX-30, the AMX-13, the Centurion Mk-10, the Chieftain and a couple of others.