There are two:
1. Ebay *sparkle... shimmer* comes with 448mb, but I am not sure in what configuration.
2. Old Studio - Comes with about 384mb. Originally used in an old studio and was shipped to us when they got a better one.

The last gen G4 is maxed out at 2gb of ram. We're doing a lot of video, audio, and other types of editing with programs that eat ram. We had problems at 1gb of memory with a dual G4... so we bumped it up to 2gb and it seems to be running fine now.