FreeBSD NAS hardware suggestions

[cruxpot]

Hi there,

I am upgrading my FreeBSD 9.2 NAS box. I purchased an old Highpoint
Rocketraid 2300 from eBay along with some large disks. My motherboard
is an A8R-MVP with an old Opteron processor with 3GB RAM with no EFI
support in the legacy BIOS (AFAIK) and I am curious whether it can
either boot or access 3TB disks in a raidz pool.

Does FreeBSD 9.2 perform well with the controller card if 4 disks are
hooked up to it?

If I choose disks larger than 3TB, will I have to make the raidz pool
"auxiliary" and not boot from a root raidz?

I am looking at Seagate's NAS line of drives since they seem to have
less DOA's in reviews than the WD red drives. Are these good for ZFS?

Any other recommendations? I am doing this upgrade because the NAS
currently has Seagate Barracuda Green disks that keep dropping off (I
posted here a while back) and I think it's related to the green
drives' firmware, which cannot be modified.

Thanks for any insight!