I'm a fan of the close paralell grip, personally. The last few degrees of rotation going upwards is far more proportional (relative to the first part of the ROM) in terms of mechanical difficulty for me.
You might want to try a static hold (at the top of the ROM) which leads into an against-your-will negative. You get fatigue through out the full ROM, plus the added benefit of definitly knowing that you've achieved meaningful exhaustion in the portion of the lift which one invariably does NOT reach upon *concentric failure* (unless they have a partner to help with forced reps).
you could work your abs at the same time, like this guy