I'm a huge fan of primes. You cannot beat the quality a prime lens gives you. Not just great sharpness and color and bokeh, but there is an certain quality about them that makes them pop, even at equivalent apertures with a zoom. Plus, they generally have MUCH less distortion than their zoom counterparts (not always, but usually).
I know you like the MF lenses, but if you get a fast prime, I do recommend sticking to AF on a crop body. If you shoot wide open, the DOF will be so thin that you wont be able to see it in the viewfinder well because crop viewfinders are tiny, and you are going to miss focus a lot.
Just my two cents! I would personally go for the 50 1.4 and call it a day. But that might be too long for you on a crop body.