Storage Server/a

[Labyrinthine]

Okay, here's my situation:

I have a tower which can hold up to 9 drives. I plan on filling the thing up with 1.5TB drives and when that fills up I'll buy a dedicated 4U tower with 20 hotswappable drive bays and fill that up with 1.5TB drives. Should give me roughly 35TB of storage. It will be a longterm project, considering the case is $300 and the drives are about $150 each. Regardless, I run Ubuntu server on it and FreeNAS, which covers the software side of things pretty well. I have a two drives - 80GB and part of a 1.5TB - which will be dedicated to backup in addition to a local backup. This will be for important docs and files which I need backed up. I'll keep a backup of my music, but the movies are just too gargantuan to make a backup of without adding another 35TB.

Regardless, my question/issue is as follows: with this many HDs, how do I get them hooked up to the mobo in a decent fashion. I'm assuming I need some sort of SATA/RAID controller/s.
Also, anyone have any ideas on how to do this better?

I know this probably isn't the best spot to ask this, but I figured I would get some feedback from  you guys in addition to being confused by the storage and HTPC nerds.

[Latro]

I can't remember where I saw it.. but there was a storage tower that had 4 internal HD slots that connected to your computer via Firewire 800 or something.  It did the automatic backups, let you know when you were growing short on space, and a bunch of other features. 

Sounds similar to what you're trying to do, although it is limited to 4 slots.  I'll try and find it for your reference.

[Labyrinthine]

I've already seen the devices. I'd rather not use them - 4 drive slots is not big enough and I already have an external harddrive if I wanted to backup things that way.

Backup is an afterthought - the main function is a storage server for my media and other large files. That's why I want 20 drive bays and the potential to have around 33TB of space.