Thanks guys and sorry for not picking up during the week.
The comments re dof have been pertinent for me, as I have tried the lenses fully open, with both the dof issues but for me also a loss of sharpness, although to be fair it's the noise I notice the most, which prompted the original post. I am wary of more glass at the moment because, most of the time, what I have I enjoy. Although faster glass would open up more possibilities rather than pushing both the body and the lens to the limit.
New body, 2nd hand or new, costs, but there is a camera body fund that gets added to as I lose weight. A great motivator. I suppose I am trying to to ensure I can make a move that is going to keep me happy for a few years.
I do need to sharpen up my raw editing skills, I use Aperture for most shots, and dabble with PSE for gross manipulation and combination effects.
Thanks again