For lefty, all you have to do is put the pots in the order you want.
Uhm... I'm not sure what you mean...

It's not the order of the knobs I'm worried about, it's how the knobs turn.
Think about when you turn the volume up on your bass... you grab the volume with your right hand and you turn the control clockwise to increase the volume.
Now pretend you're a lefty and pretend you're turning up the volume using your left hand... the control would have to turn counter-clockwise to increase the volume if you used a mirror image of the motion you made with your right hand.
Switching the wires would be the next logical solution, however, not all pots are made so the wires can be switched. Wires can be switched on linear taper pots, but not on audio taper pots, which are most commonly used for volume and passive tone controls.
Therefore... you need what are called "reverse audio taper pots" for left-handed instruments so the controls will turn the same way for me as they do for you. Otherwise, they are backwards.
Here's a link to a reverse audio taper pot, so you can see what I mean:
http://www.allparts.com/CTS-Left-Handed-250K-Audio-Pot-p/ep-4385-l00.htmI've heard that when a lefty orders a Sadowsky, they are wired "true lefty"... which is a VERY cool thing since a lot of companies out there just give us right-handed controls and act like we don't care. This was why I wanted to find out if the preamps were available in "true lefty" as well, if they were ordered by themselves.
For 18v... the answer is no. But, you could always get something like LEDs installed that run on another battery... or keep another battery as a spare inside the box.
I've had someone else tell me the exact opposite... since the Aguilar OBP-1 can run on 18v, then so should the Sadowsy since they are close to being the same thing.
I just wanted to see if I could get verification from the source.