The Doors catalogue was extensively remixed from the multitrack master a decade or so ago (Doors Of Perception box onwards), so chances are you won’t be comparing the same thing with a modern mastering to vintage. Personally despite feeling the Doors Of Perception box is pretty decent I’m no fan of rewriting history so I’d go for the originals every time.
Obviously the most collectable and valuable pressings will be US 1st pressings, either mono or stereo, and rightfully so. Good ones are worth *a lot* as one would expect. I’d certainly go this route if the price and condition is ok. I’ve got a mixture of the Steve Hoffman DCC vinyl (also very expensive these days, though I bought them new) and a couple of later issues, plus the Doors Of Perception CD/DVD box. No originals sadly!