The 5DII is an easier camera to learn and a better camera for your purposes.
A 60D would be even easier to learn, about half the price (leaving more money aside for good lenses, which ultimately are more important than the camera) and good enough to be a second shooter at weddings.
I suggest you check out the wedding forum here and see what people are using.
If you are planning to shoot weddings for pay on your own, you actually should have two cameras, several lenses and at least two flashes, plenty of memory cards and extra batteries.






