Thanks all,

I think I'm going to go for the 580 as the starter then add some no-name flashes for manual off-camera work (some on Amazon claiming the same light output for $50 - $75 even). Until they kick me out of the rink I'm going to use the 580 on its max telephoto setting for shooting ice hockey. The lighting in those rinks is horrid. The last time I shot a game it was 1/1600 f/4 @ 3200 ISO and I still had to push 2 stops out of PS.

I'm assuming the Canon Speedlites work just fine with a radio trigger? At least the 580 also has a PC connector.