First: I'm going to let the photos do the talking...
6" 27-2 - stock as it came from the factory:
Three of my 8.375" 27-2's:
With some modified "Diet Cokes":
With some Kurac Birdseye Maple Magnas:
With some Kurac GA Targets:
... and my favorite 8.375" Pre-27 shooter:
Second: You cannot go wrong with either! They are both great and I shoot both lengths. With that said - JUST LOOK at the Elegant Beauty of those long ones...

One of the great things about the design of the 27's and their predecessors is that they have that tapered barrel - wonderful for both reducing barrel weight and it just looks so cool... That makes the balance, even on the long ones very nice (you will be surprised how well the 8.375" balances with a set of nice target stocks). Just a note - my favorite range gun is the well-worn, slightly modified (trigger stop and gold bead front sight), Nelson Ford tuned, 8.375", pre-27 with 1960's era presentation target stocks shown in the last photo above. Another cool thing about the long ones, is that when you pull them out at the range, everybody takes notice...
Third: I have to agree that you should buy both and see which one you like best - as a matter of fact, you should have at least one of every length - 3.5", 4", 5", 6", 6.5" and 8.375"

My collection is very heavy on the ends of the barrel length spectrum with a bunch of 3.5"ers and a bunch of 8.375"ers.