Yup, that's exactly what I was looking for. Tried to find a way to calculate output difference between AC and DC, but couldn't figure out the "power factor" variable that the formula was looking for. They sell 14mm cartridge heaters, but I was afraid it wouldn't fit smoothly.
Shipping update tells me the seller is shipping from China, so I can expect this thing to show up between Dec 6 and Dec 24. Didn't realize the wait would be so long.