Do this. Works great. I'm running LED's and a halogen up front. Magical Pancake said he used this diagram for his turbo charged puch and it worked great for him too.
Just buy big caps and be done with it - as long as they aren't too small it really doesn't matter. I'm probably going to get rid of one of them becuase 3300's are HUGE. My lights don't flicker.
You could also do it with a 12v regulator and rectifier separately - you don't have to use the trailtech.
The whole resistor thing for your brake light is fine I guess... I think you're over complicating things trying to do that, but to each their own.