I'm looking to upgrade the brake levers on my old road bike. It has suicide levers which suck, and I would like to put aero levers on, for better mechanical advantage, increased comfort, and the nice clean look.

BUT. This bike has some fantastic grips. They're not the spongy foam, they're smooth and have a sweet diamond pattern punched in. I'd like to keep the grips, which I assume means I can't have aero bars.

So, what are the best non-aero bars, in terms of ergonomics and efficiency?