Finding "best" is not so easy (things change quickly in the truck business). I have seen this company
mentioned a number of times, but cannot offer an opinion. This company specializes in hiring contractors to haul RV's for factory and dealer. Your need might be considered a "backhaul" (a paid return trip for some haulers).
No matter who you hire, being near to Houston (a city with some very big RV dealers) should be of benefit (timeliness and price).
Rates are often quoted postal zip code to postal zip code; loaded. I would enquire having it towed flat (on own tires) and on trailer. Frankly, I would prefer
to have the A/S on an appropriate trailer for transport. Things get shook up.
Denver to Galveston is a long haul. I would expect no less than $1.50/mile, zip to zip.
80123 to 77550 is approximately 1,100-miles; so, flat-tow might be $1,650 to understand bids from the low point. Maybe $1.25 (but the economy is better than two years ago).
Bonded and insured should be prominent words on the website, as well as many years of business.