I too have steady hands, which is wonderful. I own the IS version and can tell you from experience that I have kicked myself on more than one occasion for working a shoot and realizing that my image stabilizer was turned off. Tonight, I had a product shoot with a tripod and turned the IS off, next Saturday is a family shoot. By golly I just went to my lens to turn the IS back on. It is a wonderful asset to have and one that I would miss dearly, especially during weddings. I would save up a bit more and purchase the mark ii, or do what I had to do and rent it for all of my weddings until I saved up enough to buy the thing. Either way, I would not send you elsewhere.
Congrats on the growing business BTW, that's always exciting!
I hope this helps,
-Tabor