It is probably good to note that the cracked dash issue seems to be somewhat common on the second generation Avalanches, EXT's and other trucks of that platform.
There are even Facebook groups for owners that problem.
There are plenty of threads on this forum discussing that issue.
Also, the bed panels can be had on the used market.
There was a set offered up on one of the Facebook groups just this week for $50.
That is about as low as I remember seeing for a set, however.
But, the point is, they are out there and if you find your dream truck and the bed panels are missing, you still have options.