Software raid - controller options

[Lyle Schlueter <lyle@xkubed.com>]

Hello,

I just started looking into software raid with linux a few weeks ago. I
am outgrowing the commercial NAS product that I bought a while back.
I've been learning as much as I can, suscribing to this mailing list,
reading man pages, experimenting with loopback devices setting up and
expanding test arrays. 

I have a few questions now that I'm sure someone here will be able to
enlighten me about.
First, I want to run a 12 drive raid 6, honestly, would I be better of
going with true hardware raid like the areca ARC-1231ML vs software
raid? I would prefer software raid just for the sheer cost savings. But
what kind of processing power would it take to match or exceed a mid to
high-level hardware controller?

I haven't seen much, if any, discussion of this, but how many drives are
people putting into software arrays? And how are you going about it?
Motherboards seem to max out around 6-8 SATA ports. Do you just add SATA
controllers? Looking around on newegg (and some googling) 2-port SATA
controllers are pretty easy to find, but once you get to 4 ports the
cards all seem to include some sort of built in *raid* functionality.
Are there any 4+ port PCI-e SATA controllers cards? 

Are there any specific chipsets/brands of motherboards or controller
cards that you software raid veterans prefer?

Thank you for your time and any info you are able to give me!

Lyle