What flash unit to buy.

Aloha to everyone. I'm new to this forum and have lots of questions, particularly in regards to my Canon G-5 and what flash unit to buy. I've read all the magazine articles, searched endlessly through web sites and now it's time to make that purchase. So, which flash unit works best with the G-5?

I've just started doing some wedding photography on the side, but I really enjoy doing outdoor portraits. I've studied most all the articles I can dig up about the Canon Speedflashes, the Sunpacks, the Quantums and the Metz units. Now I'm at the path in the road where I make that purchase. Of course I want something I can build on, so which works best?

Those of you out there that have had lots of hands-on experience with various flash units would be helping me out a lot as the cost of a top-notch flash unit is not something to sneeze at.

Oh, by the way, please have some patience with me as I'm new to this 'forum stuff' and don't know all the in's and out's yet.

Mahalo (Thank you).

Get a 420EX or even a 220EX, both are better than the onboard flash unit. More power and faster recycle time.

Thanks for the feedback Camo 757. Who would have thought buying a flash unit would have been so mind-boggling? I was looking at the 420EX or even the 550EX. For their respective prices, you can almost buy two of them for the price of the new 580EX.

the sigma 500 dg super (sorry, son't knwo the exact name, all i know is to go for the super) offers almost the same functions as the 580ex at quite a bit lower price. i think it can also be triggered wirelessly by only the builtin flash. hopefully someone can confirm.

Thanks 'bolantej'. I was thinking that I'd like to purchase a flash unit to use with my G-5 and look into getting a good battery system like the Quantum 2x2 to power both the flash unit and the camera. Changing batteries in the middle of shooting is such a pain. Haven't even looked at the Quantum site yet to see if they have what I need.

A quantum is a very expensive battery for that setup. I'd get the Sigma Super 500 or Canon 550EX, for the manual controls, as I don't know how much control over the flash the G5 gives you.