The Zeiss Distagon 21mm is widely regarded as the sharpest wide-angle ever produced. Only goes to F2.8 though. The Canon 35 F1.4L is generally considered to be spectacular - one of Canon's best. The 24 1.4L isn't quite as highly regarded, but still an excellent lens.
FYI - Infinity is not always infinity. Taping a lens there may yield terribly out of focus results.
Yes to the infinity. When I used Pentax 67 infinity seamed to be a constant, I could stick it and forget it. Now with Canon I'm not shure the camera always knows where infinity is. Looking back the other day at some images shot on colour neg, they look a lot sharper than any digital I have (various Canon and Kodak), despite slower shutter speeds. So much so I've just bought a colour processor and intend to mix in a bit more film. I looked at some Reala images applied a hint of noise Ninja and grain became a non issue, if I look at Provia grain IS a non issue. I've just ordered some 800Z Fuji, I'm going to see if it's extra latitude means it can handle under exposer better than shooting the Canon at 1600 -3200iso. It's OK shooting digital in a studio at 1600iso and saying look no noise, it all falls apart when you shoot under Street lights.
I think the 35mm f1.4 might be an answer, it might not be the only answer, I'm also going to test a new Nikon against my Canons and 67 film, just waiting for my Makina 67 to come back from a full expensive service and the film to turn up. Watch this space!
Kevin.