Hi Brendan,
A 14" corrector will take a fair bit of heating / power. I would suggest that you go with something like the Kendrick ZapCap from Bintel. I don't know if you really need a dew controller to go with it though. I run mine directly from 12V supply with no problems.
For 12v power, I have converted an old PC Power Supply as shown in the attached link:
http://www.wikihow.com/Convert-a-Com...b-Power-Supply