I make my living as a photographer and always used to shoot Canon 5D until the Nikon D3 came out, which suited me far better.
Most DSLR cameras today are very good, so the thing that has more effect on the image feel and quality, is the quality of glass used.
Don't fork out thousands on a new body when the improvement in image quality is only really noticeable if you print over A1 size, instead make sure you get great glass and the improvement can even be seen at screen size.
Primes 50 80 100 135 are high quality but inflexible, but the 2.8 zooms are almost as good and far more flexible.
The 70-200 f4 Canon is a truly awesome lens and worth its weight in unobtainium, whereas the 135 DC lens and 85mm1.4 (OR1.2

??) are incredible.
Great glass trumps camera body every time.