512mb video card, is it enough?

As a photography company, I am considering an Imac. I'm not sure if I need to go to the 27 inch monitor with the 1gig video card. The 21 inch imac doesn't come with a 1 gig video card. So, at this point, I'm not sure.

The apple guys at the store couldn't give me an answer either way. The dude at 1800 Apple said I should buy the 27.

I would appreciate any advice, will the 21 inch quad core with 512 mb video card be enough for heavy photo editing, or should I get a prostitution job on the side to pay for the 27 inch?

Thank you in advance.

512MB should be fine. More than that is only really useful for gaming.

+1 what cwa107 said.