Well, I got a reply... The sheet that I posted earlier can NOT be cut.
For that you have to buy the "custom pattern sheet" (part number "bA4-BG"), which is A4-sized and $39.20.
After being cut, each new smaller sheet can be powered by 4 AAA batteries in a "iSS3.1" inverter (at $7.50 each), connected to each sheet's positive and negative tabs via gator clips.
-OR-
You can buy 2 of the A5 sheets that I originally posted (for $19.60 each), and 2 power supplies, but you don't really save anything, AND you have to figure out something to do with the excess material since it can't be cut.