It depends on how you are going to use your suburban. If you plan on going in and out of the back with large objects...barn doors. If you plan to have seats in the back and only put small items such as picnic baskets, tool box etc....clamshell tailgate. I like the look of the clamshell tailgate and the lift gate window for better viewing, ventilation (caution if you have your tail pipe coming out the rear) I like the clamshell tail light too.
To answer you other question on if you can mount either style doors, a simple answer is yes....but there is some problems if your Suburban came with a clamshell and you want to convert to barn doors. There is no reinforcement for the door checks. The problem with converting from barn doors to clamshell is there is no support for the lower hinges (important) and you will have to find tailgate retractors and cables as well as other pieces to complete the conversion. You will have to cut the lower body panel to allow the hinges to go through too. You can purchase the body plugs from several vendors to close off the barn door hinge holes.
......g
