Livestream + Wedding

[PhilipGrey]

Hey all,

I'm looking to livestream my wedding and frankly, my head is spinning with all the equipment and workflow options. We'll be renting a camera from somewhere, but not sure what to go with, and if what I'm looking for is possible.

Ideally, I'd like to rent a camera that can
A) Record locally in HD
B) Output live in SD through firewire to my MBP.

I know you can easily do both of those things separately, but can I do them together at the same time? Would this work on the Canon XHA1? Other camera suggestions or general ideas?