7 Macs..need something to backup and share files wirelessly

Hello, I am currently in a tough situation. At my house I have seven Macs
Here is what I have and what OS its running:

iMac 10.5
Mac Pro 10.5
PowerBook G4 10.4
MacBook Pro 10.5
PowerMac G5 10.5
eMac G4 10.5
iMac G3 10.4

As you can guess..It is very hard to exchange files and backup all of these computers. (They all have important information on them)

I have thought about buying an Xserve G5 for all of my backups. But I was hesitant about compatibility issues. Does anyone know if there are any? Also, does every Mac need to have OS X server on it to be connected to the server?

I would like to exchange files wirelessly also.

Basically, I would like to have all seven of my Macs to be connected wirelessly to some sort of "base" to backup files. Also at this "base" I would like to have control over what these Macs do.

Another question I had was, If all of my Macs do require I had OS X Server running on them, could I still use iLife and such Applications on them?

Sorry this is such a long post. Any responses will be greatly app.
Thanks

If the computers are all on a network together, they should already see each other. You will have to enable file sharing though. This is done under System Preferences>Sharing>Services>select Person File Sharing (for Tiger/10.4 anyway. Leopard should be close to the same).

As for backup, I've noticed Apple's Time Machine software will work with any external drive I plug in, so I'm pretty sure if you get something like a Drobo or other NAS unit, you could share it across the network for all 7 Mac's, and use it for all the backups. Someone elsewhere has said that Time Machine stores info based on computer ID, so Time Machine backups from multiple machines wouldn't be an issue.

Hope that helps.

Correct, Although I have come to find that time capsule is not very reliable and has often lost connections. I would like to have a centralized storage, and control over what Macs can do what.

I would also like to update all of my macs from the server? Is that possible?

For that, you'll have to wait for someone else to chime in. What I posted above is the extent of the info I've gathered lol.

Lost connections? Could be something simple in the network setup that needs updating or adjusting.

For your type of situation you probably want to look at the Apple Remote Desktop software. This will allow you to manage up to n number of computers from a central location. The reason I denote 'n' computers is that there are different licenses depending upon the amount of machines you have

Apple - Remote Desktop 3

For the centralized file repository, you will most likely want to invest in a good NAS solution, either that or convert one of your machines to a centralized file server. For the amount of machines you are talking about, a good NAS product should have built in networking. Google around a bit you should get a good idea of the prices/capabilities.