Plain vanilla dvorak is best imho. Yes, it does move 3 or 4 keys such as {}: etc out of the way, but you quickly get used to them in the new position, and after a while it makes no odds at all.
The pay off comes in being able to use any random pc - flick the keyboard layout to standard dvorak (which is on just about all PC's, unlike most obscure programmer layouts), and away you go. If you're used to a non-standard dvorak layout, and are forced to use a normal dvorak layout on a qwerty labeled keyboard, I suspect you're in for a whole ton of backspaces (and curse words).
I've only been using dvorak for a few years, but I can't imagine programming using anything else. (Especially with vim, the dvorak layout seems to end up with lots of the keys in much handier positions =)
oh, and as mentioned above - kinesis contoured keyboard is the way to go if you're considering changing layouts for R.S.I issues.