Mike, I should probably clear up the CAD thing. I think I said CAD-like earlier.
What I'll be doing is 3d model rendering for items to be made on a carvewright machine. It's basically a cnc device for the woodshop.
I don't think the files will be all that huge.
I use Acronis and do constant incremental backups. I don't generally make .tib files, I like to back up all the files, verbatim, with no compression. That way if one disc fritzes, I can just pick up where I left off. I don't have to stop and go fetch a new hdd, etc. I'm also not bound by having to have equally sized hdd's.
Those things are real problems in small town USA where I used to live. Here, near Cleveland, things are more readily available, but I still simply don't need or want the added limitations that RAID puts on me.
I used it long ago, and ultimately walked away for the reasons I mentioned.
The speed isn't necessary, and I've made really good habit of constantly backing up. Most people don't do that. I've had to learn it, and I don't ever want to lose it.
I will admit that the instantaneous backup that raid 1 offers is very enticing. It even makes good sense. I'll continue to carefully consider it.
If we ever start using our own server, I'll make it redundant and keep one offsite. I'd far rather be in control of my own fate than sending files up to a company who could become insolvent fifteen minutes ago.

I can always back up to a disc and put the data in a firesafe, too. That stuff is all manageable, and I'm not scared. But that's only because I've always backed everything up by hand for so long that it's just second nature. Cripes, I can't even make a long post on a messageboard without copying it before I press the "post reply" button. That's how bad I am.