Backup camera body

For all you Canon guys on here......

I currently own the 5D MKII, but am looking for a second body as a backup. I do not want to spend a whole lot of money (as I don't really have all that much to spend), so I was looking into something used. I have seen a few T1i's and XSi's but since getting the 5D MKII I have grown quite accustomed to the bulkier body. I found a used 30D today for a good price and if I remember correctly, that was one of the better cameras out there a couple years ago, and its body is the same size as my 5D. I know its only 8.2MP and it has a crop sensor. An engineer at my last job had his own business as a professional photographer and used one of those and had many great captures with it.

I have also found a few used 40D's, but they are little morethan I think I am willing to spend on something used.

I am leaning towards the 30D if anything since like I said it will fit my hand the same as my 5D, and it looks as though the controls/buttons are laid out roughly the same as my 5D.

What do you guys think?