Appearance of the urethane and vinyl wrapped dash pad is the same when installed, the vinyl one will crack in 15-20 years just like the originals did unless protected from the suns UV rays and extreme heat, the urethane one will look the same in 20 years as it does when installed as they will not crack ( though it most likely will be dirty than when installed
) If you want to be as close to original as possible go vinyl and keep it protected from UV rays when not driving ( windshield screen ) if it doesn't matter that its not vinyl wrapped as they look the same installed go urethane.
We carry both in stock and you will find them here both on Sale Special prices
http://www.gmcpauls.com/SALE_SPECIALS.htm
GMCPaul