PowerMe is right. If weight is not a concern and you need some serious security, go with ABUS X plus but it's heavy. I would also suggest ABUS 5000 series, which are lighter and easier to carry around. EVO eco has plenty space near the seat tube.
I've decided on Abus, the Granit-X Plus 540 U-lock (I'll use that for the rear wheel/frame with a Kryptonite cable looped between the lock and saddle) and a lighter Abus Steel-o-Chain 1500 for the front wheel. And it's probably more than I need for security...Fortunately I don't need to keep my bike locked outside at work, so security for other times, but no sense going cheap after I just spend 3K! At home I keep the Ulock waiting for me as the front porch lockup from now on. I've spent a week dragging the City Commuter up and down a flight of steps.