Do I need to rent a normal range zoom?

[brianleighty]

So I'll be shooting a couple weddings in March and I'm starting to think about gear for it. While the wedding I did in early December was with two full frame cameras, my wife was one of the brides maids so I was able to have both cameras with me with one having my 24-105 and the other a rented 70-200. My question is this. Do I need to rent a normal range zoom to make sure I don't miss shots? I'll give my wife the 24-105 so I'll at least have some fall back there. I normally use the 70-200 for most of the ceremony and a good part of the reception as well. The main things I'm thinking of are the cake cutting and wide shots of people dancing where you need something wide. My thoughts are either #1, use my 40 2.8 lens for this. I always have a hard time using this lens just cause of it's low price yet it's a very nice lens so maybe it's just in my head and that would a good option. The other possibility would be to rent the Canon 35 1.4 like I did for this last wedding and have that for my wider angle option. I'm only wanting to rent one wide aperture lens though and I'm trying to decide between this and the Sigma 85 1.4. Now one other thing that factors in and is part the reason I'm wondering if I can get by without renting a normal range zoom is I also still have my 50D which I can either have ready to go with my Sigma 10-20 or Tamron 17-50 as a backup as well. Full frame is obviously a lot nicer though so I wouldn't want to be using it more than I'm using the full frame or else what's the purpose in renting the full frame camera then? So any thoughts on this? Thanks