Staying on the subject of lenses, what you could do is rent one for a week and see if it fits your needs!
It would be cheaper than buying one outright and give you a good idea of it's capabilities.
PS
As I type this the harsh reality of a working photographer is at play. I'm sat uploading, describing etc over 100 images to Getty.
PPS I think I have 1000 or so still left to sort out
