Help Deciding G5 tower vs. imac G4

SO here is the deal. My own personal machine is an imac dual core intel.

But in order to keep my wife and mostly the kids off of it (I use it for work and music) I want to supply other options in the house.
We have an old g4 13" macbook and that's great for checking email in front of the TV .. now here is the dilemma.
a G5 imac that I put in the kitchen for the family died (shocker)
I broke my sons G4 quick silver in his room trying to take out a drive (he's 9 and loves loves loves garageband - we are a music family
so now we have no computer in his room or in the kitchen for family use

I now have one G5 tower and one imac G4

I'm not buying a new machine ... so which one goes to the 9 year old for garageband and whatever other photo / video stuff he wants to explore (I want to encourage him)

and which one should go in the kitchen as a family / check your email surf and watch hulu on?
The kitchen computer will also be used for home work and I will put an airport card in which ever will go there ... I don't want internet in my sons room unsupervised.
Put the G5 / better machine in the kitchen ... or let my son beat that up for garageband use ?? HELP !! and thanks

nothing bad ... I cracked the housing of the optical drive ... It's to annoying to put it back in and being that I have these other machines I figured that I would just swap it out ... it was a super drive and I already put it into the G5 tower (there was no drive in that machine ... probably took it for parts at some point)