Denise,

Congrats on shooting your 1st wedding. First off, the best advice you'll receive will be from both clemmb & iND. There are some others on this board that have dipped their toes in the wedding pool but these two guys actively shoot. I have close to 20 weddings under my belt but I am much less active than I used to be.

Gear: Use what you have and what you know. You'll need one more body. I'd rent another 7D. Weddings move quickly. You don't have time to react. You'll need to make changes on the fly. Use what you know.

Like iND said, he can shoot 90% of a wedding with just one lens. In your case that will be your 17-50mm 2.8 OS. I would have that on one body and your 50-150mm 2.8 OS on the other. That's really all you "need". I would also have your 430EX on one body and your 580EX on another. Leave your light stands and triggers at home. That is way more than you'll want to/be able to deal with on your first gig. Practice controlling flash with bounce. You'd be surprised what you can do with on-camera flash. Not everyone starts off being Jerry Ghionis. No flash allowed at the church, that's fine, crank up the ISO and shoot wide open. OS will serve you better than your faster glass will. Although weddings move quickly, during the ceremony, people don't. You can shoot as slow as 1/50 with good results. Your 135mm f/2 on your 7D will require >= 1/200 to handhold. That's the difference between ISO 1600 and ISO 6400. Although, use enough ISO to get the shot. Grainy = better than Blurry! You can use your primes for creative DoF shots but your bread and butter will be your 17-50mm 2.8 OS. You can use your macro for ring shots.

Memory Cards: Grab 2 more 8GB cards and you should be set. I usually use 4 cards for a wedding and I shoot RAW. I'll swap out the 1st 2 cards after the ceremony and then use the last 2 for the reception. I now use two bodies at the reception but I used to only shoot one. Lugging two bodies all day is exhausting. It's neccesary for the ceremony though. You can sneaker zoom at the reception but you do not want to be obtrusive at the ceremony.

Batteries: Have at least two sets of batteries for each flash (in your case >=16). Charge them the night before. Also, have >= 2 batteries for each camera body. You "should" be able to shoot an entire wedding without having to swap batteries in both your camera and flashes but you can't rely on should. Why will your batteries last all night? Because you are shooting at f/2.8 - f/4 most of the time and >= ISO 800 to ensure quick recycle times.

So what do you need? (1) 7D ($75 for 4 days from lensrentals.com) (2) extra camera batteries ($30 = $15x2 for 4 days from lensrentals.com) (2) 8GB CF Cards ($15 = $7.50x2 for 4 days from lensrentals.com) for a grand total of $120. Based on your hourly rate you're back in the black after the 2nd hour.

Lastly: Chase light, compose, think about what you should exclude from your compositions more than what you should include, have fun :-)

PS: Pack some snacks (banana, granola bar, bottled water, etc) They may feed you but eat when you can and stay hydrated.