I actually did something similar to what you are talking about. Wanted to take my bike from MN to TX. Was towing a trailer also. I used 2 2X10's, side by side, laying flat and screwed them together. At the front I attached a Harbor Freight wheel chock. I also screwed a board across the front (making a T) that was the width of the truck bed. This was a 2002 Dodge Ram 1500 with the short bed also. I added similar blocking at the rear, screwing it to the 2 flat 2X10's. In essence what this did was to keep the 2X10's from moving fore or aft, or side to side.
I added eye bolts on the front cross piece and strapped the front of the bike there. I went to a weld shop and the cut a 2" square steel tube, the same used for tow hitches, to the length. I needed to clear the tailgate being down and the added length of my bike support. They also drilled two holes all the way through at normal use and long use (in the event I needed to use it with the tailgate down again), and a hole for the ball hitch. I think I paid a total of $27 for this and it took about 15 minutes.
I cut the boards short of 10', closer to 9 if I recall correctly. To load and unload the bike really wasn't bad. If you drive around an area a little bit, you would be surprised at how many places have loading docks or raised areas in the back of a business. To load mine, a local college 3 miles up the road had a loading ramp. I backed up to the ramp with the tailgate down until it almost made contact with the tailgate and bumper. I used my regular folding ramp and it was pretty much level at that point. I walked the bike into the truck bed and secured it down.
In Texas I found a spot about a half mile from the location I was staying at, where the road was higher that the shoulder. I was able to back up to the road and the tailgate was only slightly higher than the road. Used that location for unloading and loading it back on when I left.
The wood bike base never moved during the entire trip and the bike stayed rock solid on the platform. It might have been a little over kill, but it worked well.