[G4] Motherboard swap

[Doyle Potenteau]

Hello fellow listers. Longtime Mac user with a question.
Just purchased a Gigabit model sans motherboard for dirt cheap. Plan  
to stuff a new Gigabit motherboard inside to revive the aging beast,  
but am toying with the idea of maybe jamming in a different  
motherboard, like, say, a Digital Audio or a Quicksilver version.
I know there are differences between the two, such as 3+1 slots  
versus 4+1 slots, and that the audio plugs are arranged differently,  
but wouldn't it be possible to swap out the rear housing? After all,  
it seems all three use the same form factor and there isn't much  
pricing difference between those three motherboards, though I realize  
this possible modification wouldn't make much financial sense.
However, in saying that, I remember telling my ex father-in-law, who  
is a housing contractor, before building my first house: "Build a  
house? How difficult can that be?"
For those who don't know what I'm talking about -- the motherboard,  
not the house -- here's a link:

http://docs.info.apple.com/article.html?artnum=58418


Thanks in advance for any answers and/or comments.
Doyle