What's better a PS3 MGS4 60gb or 80gb bundle??? < AD ERROR. was 40 and 80

[Rickyknows2]

I need you help. Just found two system on hold for me today until 5pm. OK, so I found two PS3 MGS4 bundle packs. One of them is the 60gb for $449 and the other is the 80gb for $499. Beside the $50 and 20gb, what the differences and what the best one to get?

Someone told me that the the new 80gb runs everything better (except for old PS2 games), but that the 60gb is better for playing old PS2 games. Is it still possible to upgrade the hard drive on both of these system? Does the new 80gb & the 60gb both have usb's ...etc or does the 80gb have more features.

I am buying it for my sons, but also for the blue ray player. Thanks in advance.

UPDATE: Fry's Electronic Ad Error - it shows a PS3 60GB w\ MGS4 for $449, it should have been 40GB not 60GB!!!