I am going to go with the recommended wall wart for the B1 which is 18 to 24v. I will have to use a step down voltage converter. You can find them for about $5. I will have my Electrical Engineer friend help me with that.

EPS240025-P5P CUI Inc. | Power Supplies - External/Internal (Off-Board) | DigiKey

Here is the actual part list for the B1. It's about $150 for the stock parts, but I will be using better Caps and some boutique resistors, about $250 in parts.

Nelson Pass B-1 preamp kit