Maybe the Selle Italia SLR? There is a new model in the Carbonio series that is a flow-through (ie, cut-out), and the Carbonios are very plain, no stitching, no seams. I would steer clear of the Gel Flow model.
Are you really sure you want to go through this again? During my saddle search I tried 14, most of which had cut-outs, and the experience was horredous. I also ride a Fizik saddle, which does not have a cut-out. It is not terribly comfortable in the drops either. But I will sacrifice that for overall riding comfort far superior than anything in the cut-out world.