All Classified forums require a Site Supporter subscription. It is only $25 per year and you can buy and sell whatever you like on the forum. To become a Site Supporter, go to Your Profile and select "Paid Subscriptions."
Where are you located?
Sometimes you can get lucky and find one in a junkyard. Down here they go for about $500.
Cut the floor out of one of the long beds. You said your not looking to make a show truck, and you can cut the floor down to fit.
what year truck you got?