I put mine in the trailer. Put them up near the front so if someone does get in they will not have time to discover them. This assumes you have a closed cargo trailer. I used my 16' cargo trailer to move my entire household (35 years worth of stuff) 850 miles. This included my lathe, mill and gun safe. It took seven trips as I recall.
I move my trap gun over long distances many times each year as I travel to shoots. Gun cases work for this as well as does wrapping the guns in a blanket. Moving a heavy gun safe seems to me to be the bigger problem. When you load the truck, do not put the gun safe on top of the guns. You could load the safe, wrap the guns and then put the guns back in the safe.
andybull, nice rigging job! I just had my two boys lay my safe over onto a four wheel dolly that I made. Then I winched the dolly up the ramp door into my 16' carco trailer. Your system looks to be very safe. Not everyone has two football linemen for sons! By the way, my oldest (6'-3" and 325 lbs) claimed he could just roll my 800 pound safe up the ramp and into the trailer - he was WRONG.
Put the guns in gun cases. I had a wooden box that was just long enough and tall enough for the guns. I put them in gun their gun cases, put a layer of guns down on a blanket and then rolled the blanket over, then another layer of guns. I did this over and over till all the guns were in the box. Padding is very important because of rough roads. Put a harden lock on the trailer so someone can't use a pair of bolt cutter on the lock. Also on your hitch lock that also so a bolt cutters can't remover your hitch.
One thing I do whenever I figure I will be gone from the house or on the road with guns and they may not be in my direct possession is to remove some small but vital piece that makes the gun unusable.
If I am away from the house, I will store these small parts at a friends house or maybe take them with me. These parts might be a bolt from a rifle, a trigger group, a revolver cylinder, a barrel from an semi-auto handgun, the lock from a muzzle loader or other such part. That way if someone does get to the guns, they have nothing more than a club. The follow-up is that if they do take the gun, they may just try to get a replacement part from a gunsmith. Since the gunsmiths in the area will be notified, anyone asking for one of the missing parts becomes a suspect worth investigating.
It takes only a few seconds to put the part back in and make the gun usable again.
This was something I also told parents to do with their guns at home if they had small kids and could not afford a safe or lockable gun cabinet. At least they could afford a small lock box to store these parts and the kids could not get a usable gun.