Pulling a trailer, I'd definitely want an IMAC&C for it.
Imac&c hch1 civic - Insight Central: Honda Insight Forum
Just putting some kayaks on top of my car made it way too assist-happy at highway speeds, but clicking off assist will help save your battery from ECU constantly wanting to cycle it. I imagine your hybrid battery ($$$) will have a significantly shortened life otherwise.
You can breadboard your own from scratch and use the free version ($10 in parts), or $50 gets you a PCB and the full software (this is what I've got), you have to add about $10 worth of parts to finish it, or Bumblebee Batteries sells completed units (don't know how much they cost).
Just a thought (from a happy IMAC&C owner).
Sam