I don't necessarily agree that you have to switch to FF. Yes, 5D/5DII are able to do a bit lower light shots. But 7D is pretty darned good at low light too. You might be able to make it work and if you shoot with flash (when allowed) might not have too many problems.
But, I do agree that if you are going to be shooting weddings for pay, you definitely need a second camera body. I like to use two matched cameras, so I can have two lenses set up and switch between them really seamlessly.
There is also something to be said for using crop combined with a FF camera. 5DII and 7D play together pretty well. So long as you don't have a lot of "crop only"/EF-S lenses, you can really leverage your lens kit with two different camera formats.
If you stick with crop, probably should get the 17-55/2.8 or 24-70/2.8. A "standard" zoom can serve a lot of the time and will likely see heavy use.
But there will be occasions when f2.8 just isn't fast enough or doesn't blur down backgrounds adquately. That means primes.
You already have 30/1.4. With that in your camera bag already, unless you feel constrained by it in some way there's little reason to get 24L or 35L (so long as you stay with crop camera). One not too pricey option would be to compliment that with 50/1.4 and 85/1.8. Far more expensive, more specialized 50/1.2L and 85/1.2L are the "top of the line", uncompromising choices for wedding photography, but slower AF performance and focus shift somewhat limit these to portraiture lenses.
135/2 might serve well, too... less necessary if you stick with a cropper. It's really an "essential" lens for anyone shooting portraits with FF, though.
Eventually plan on upgrading your 70-200 to an f2.8. IS is nice to have, either the original or new Mark II can serve well. I wouldn't put this top priority if you continue shooting with APS-C.