Moving by Truck from Bangkok to Vientiane

(My apologies if this is the wrong section for this post)

Me, my two cats(have paperwork), and some boxes/small furniture will be moving from Bangkok to Vientiane in a few weeks. I'm trying to determine what is the best method.
I usually take the train up but don't think I can manage moving all the boxes and items from Nhong Kai to the border train and then a truck on Laos side.

Ideally I'd like to hire a driver or rent a car myself. Issues/concerns so far:

-I've spoke with a few drivers and they aren't willing to cross the border, this is not helpful. Do you think I can find a driver/company that could do this?
-If I rent a truck and drive myself, will I be able to cross border with? Also, I'm pretty sure I can't return it in Laos and will have to drive back to BKK.

-Is car crossing the best options for avoiding duty and hassle with cats, compared to air or rail?
-Another option is to go with cats by train and have a company move my stuff separately?

Thanks for input, any recommendations for moving companies or truck rentals in BKK helpful too!