New fireplace wiring question

Awesome - quite the thorough reponse! Well I'll be heading out to check on the trailer this weekend, as it's stored indoors off-site. I'll pull final dimension from the cabinet, do my homework and make a decision on which fireplace to choose.

I won't be able to execute the install until the spring, but I will be sure to update this thread - maybe do a write-up.

Thanks for all of the responses!