I did end up finishing this last week. I used a non 12V assisted module. Works great! Lights are nice and bright and everything works perfectly.
As cougar stated. if you are using many lights on the trailer, a 12V assisted module is a great idea.
As I see it, an Impreza probably shouldn't be pulling a trailer that is so big/heavy load capacity that it has many lights.(there are always exceptions)
thanks for the help guys!