The 16-35L vs the 135L makes little sense as they both are at two different ends of the focal length spectrum. You need wide-angle and you need telephoto. I highly suggest that you not buy these lenses if you only have 2 weddings booked. If you have just started, it might be better to rent the equipment as you go - this allows you to see how you mesh with equipment and what works for you. A lot of times, we think something will be awesome, but then after using it, it turns out otherwise.
I would recommend investing in lighting first as it will directly assist you in upping the complexity of your compositions.
Next, I would suggest getting a camera body that really suits you (body is something you should just go ahead and buy as renting it isn\'t very cost effective).
Lastly, I would invest in accessories like light meters and expo discs.
Remember, the more overhead you cut down, the more you have to invest in advertising. If you are not booking 10 solid weddings at non-discounted prices, then you should not be investing in L glass and the sort. If you do, at the end of the year, you\'ll find up spending more than you made. If lenses do become a neccessity, first dabble in the non-L gems - Sigma 50/1.4, Sigma 70/2.8 macro, Canon 85/1.8, Canon 100/2, Canon 50/1.5, Tamron 17-50/2.8, etc.
