Right, I have taken your suggestions on board and you are right about the weddings and I have decided to push the boat out and get all of the lenses. FYI the 70-300 has got some great reviews and has been classed, by some, as a hidden L lens, and the STM, from the limited reviews I could find, is sharp throughout the whole zoom range.
I have joined a photography club in my area and have met a few pro's that I will ask to work with as a second or third.
Any more advice that you have would be greatly appreciated.

MoNkEy.