truck cover that fits cab...then bed

[luvbowties]

Anyone found a cover(to be used for inside storage)that fits down around the cab and then extends 'along the bed'? Most appear to taper from back/top of cab down to top of tailgate like a sliding board, creating a 'bunching up' of the excess. Trying to avoid taking the 'taper-type' to an upholstery shop if possible. *Short bed stepside preferred; short fleetside would be acceptable.
Thanks for any help.
Sam