Two macs with a design workflow. Suggestions!!??

Look up version control software.

Also, I'm wondering why you both need to be working on the same files at the same time? I think the best way to manage the files is from the outset where you divide who does what and keep the work files separate. There are a ton of options but it depends on what you're doing. Flash, webdesign, print design... etc, all have different work flows.

If you want to do this on the cheap without installing any more software, then just hook up an external drive to the main machine. Everyone works and stores their files on their own machines. But when it's time to hand something in or trade out a file, then just network into the external "project files" drive. That drive is only for sharing... not for storing master files that the individual is working on. This way the users won't be working off the drive and will only be delivering to it. You could even set up folders on the external project drive with project name and individual folders for file input. Whenever someone sends a completed file to their folder on the external, they just tell the other designer they sent a file.

Finally, there is an even easier option. You could bluetooth files back and forth. I've done that in a pinch and it worked fairly well. But in your situation, I think having an external drive dedicated for file storage (like a server) is the best option.

 

If that other server you mentioned is managed by an IT person who does IT stuff like backups, etc., then I think that is where you want your important files to be.

You mentioned having some money for an external drive. Maybe it's possible to offer to budget for more storage on the server so then the size of your files won't matter. Presumably the server would be always up so no issue if you turn one Mac off while someone else needs access to files.

Otherwise I would use one of the Macs as the file server + Time Machine to backup on an external drive & also have an offsite backup plan.

Subversion might be a good way to go if you want a file repository with version control.