I was going to suggest "just doing it" but if you have to farm out the welding, it's not going to be cheap unless you have a friend that will do it for a six pack.
If you go the wood bed route, the front header panels are different, so be sure to get one for a wood bed.
Basically, you cut 12" out of the front, 8" out of the rear, and as long as you eliminate the "middle" braces, you've done it right. The other braces will line up with the factory holes, exactly like a factory shortbed.
I've done 2 of them now.
