Most experienced haulers will also tell you not to wrap for long journeys.
I wrap for 4-5 hour trips, any longer, and in hot conditions, the wraps will slip down no matter how tightly you wrap them, and your horse will get tangled in them, or you will have to remove them at the 4-5 hour mark anyways.
So, I would say not to put anything on the legs for a long journey.
Most horses will stock up on hard ground. This is why I have portable stall mats for my horses when I take them to shows and they are on concrete. As well I have a set of "Soft Ride" boots that I use on my main horse for hauling and walking around on strange ground. Both the mats and the boots drastically reduce stocking up. I don't have hind boots because they go just under the fetlock, where he has chronic scratches, and I do not like to irritate the area, but you can get them for all 4 legs.
I would recommend first getting the horse examined by a veterinarian and a comprehensive plan for managing her arthritis developed. Then once a regime of Legend and/or Adequan has been established, the swelling and soreness should be diminished. Also talk to him about management while hauling. For horses who are competing with drug restrictions (mine is 0 tolerance as he is a CDI competitor), Legend is acceptable to use and will reduce inflammation caused by standing in a trailer for hours. If the horse is under less rigorous restrictions, bute during the trip may help (talk to your vet!) but can also mask signs of shipping fever so beware and check temps often.
And look into the Soft Ride boots - they are becoming more and more popular with performance horses because they are a drug free way to limit stocking up.
Liniment has fallen out of favor with most modern vets and equine practitioners, because of it's limited helpfulness, and potential danger along with showing up in drug tests.
They say money doesn't buy happiness -- well happiness doesn't buy horses!