[X4U] Using a Quicksilver G4 as a NAS?

[Neil]

I have an old Quicksilver G4/733 with 1.12gigs of ram and running Mac  
os 10.4.11.  I need storage.  So, I'm thinking of adding a couple  
SATA cards, pulling the existing drives (even the DVD), and  
installing 6 or 8 SATA hard drives.   I know that can make a lot of  
heat, but I think I would rarely access more that two drives at a  
time.  I don't need RAID.  An 8 bay NAS would be expensive, and while  
an 8 bay USB enclosure would suffice, that would run a few hundred  
dollars too.

My questions:

Am I better off getting a USB enclosure?  If so, is there one in  
particular that I should consider?

If converting the G4 into a NAS makes sense, which SATA controller  
card (inexpensive, Mac compatible and bootable), hard drives (low  
heat)?  Should I run the Mac os or try Linux?  Thanks in advance.