red55: Mar-K beds are made to directly replace the original bed parts, and are designed to have the same appearance and bolt together the same as stock. When you buy a Mar-K bed, the parts fit together without drilling, cutting, welding or repositioning on your chasis. We use spot welds like original, exposed bolts as original, and bed to frame attachment is the same as original. Many custom options are available, such as hidden bolts, stainless angles, delete stake holes, tailgate without chain latches, etc as outlined in the catalog.
Hopefully someone on the board that has personal experience with the Pros-Pick and other manufacturers beds will describe the differences. Pros-Pick beds are generally meant for custom or street rod type applications where stock appearing bed is not desired.
We suggest that you obtain catalog information and installation instructions from suppliers that you are considering. Carefully study them to be sure the results are what you are looking for. This is a major investment and you want to do it right. View the Mar-K catalog page for your bed kit at
http://www.mar-k.com/lateGMbed_kits.pdf or order a catalog free on line.
Mar-Ktech