I'm at a small company and we (the IT department of two) manage <100 client computers and a handful of servers. Currently we're using a company's appliance to handle backup; it does a small backup every night and a full backup every weekend, and a guy comes on Wednesday to take an offsite backup drive (and gives back last week's drive to swap with it). The backup is done only on the servers' hard drives, because our client computers and employees make sure not to store anything worthwhile on their own computers. So it's a pretty simple situation.

Lately this system, mainly the appliance, has been having problems, so we are looking for an alternative. I'm researching other companies but also looking into what we might expect from trying to do this ourselves. There will undoubtedly be a large learning curve, but hey, that's what serverfault is for, right? :)

So anyway I was looking at Bacula. Feature list sounds great, documentation is plentiful, but it's only software. So my question is, what is the ideal backup server to run the Bacula server software on? And not only the server but other related appliances.

Our current backup appliance uses only hard drives, not tape drives. It has several plugged into it at one time, in hotswap bays on the front of the machine. I couldn't help but notice though, it's hardly more than Windows XP with hard drive bays, a PCI eSATA card (which connects to another appliance extension piece with 2 more bays), and their software. Since the company will take back their appliance if/when we cancel with them, where can I go to configure a server with these kinds of things? And should I consider switching to tape drives? What other concerns should I be thinking about when I pick out hardware for a backup server?

Maybe I'm being naive, I'm sure Dell (and any other computer company) sells them in the small business section of their website, but I wanted to make sure that there's not some other more recommended place that other companies are getting their hardware from, and that I don't need anything special for Bacula.