By all means, get them balanced. I replaced mine (the front and rear outside), and they were balanced by the vendor (Discount Tire Co). I do not believe any tire should be mounted and not balanced. They are too expensive to not follow normal balancing and rotating routines.
Welcome to the forum..... :laugh:
Archer is absolutely right... and get all the tires balanced, not just the front.
What happens if you have a flat on the trip and have to mount the spare ? Or what about when you rotate the tires each year, are you going to make a special trip to a shop that can handle a big rig like you have ?
I have all my tires balanced when buying new ones,... yes even the spare.
Most tire places will mount and balance the new tires for free when you buy from them.
Oh yes... don't forget to have all the valve stems replaced when buying new tires, and I recommend installing the metal stems, not the rubber ones..