If you decide to go the Canopus route, Simply Computing on West Broadway has them for $299, which is the cheapest I’ve found them in Vancouver. They’ve got a couple in stock right now, too.
I’ve borrowed the ADVC-300 from work, and it’s a pretty solid little device. Firewire-powered, analog input for capturing and analog out for monitoring. The DVI-to-RCA adapter Apple offers is not in the same league for monitoring. I use one for Shake output, but if you want Final Cut support, Canopus is probably the way to go.