From the point of view of most on sites like this one, Pontiac quit building cars in 1979. That was the last year of the Pontiac V8 (the short-decks don't "count"). So, no, Pontiac shutting down will have no effect on the availabiility of Pontiac engine parts. We haven't bought anything from them (Pontiac Division) in over 20 years anyway.
Pontiac or Chevy? Well, it's true, Chevys are "easier" and a bit cheaper IF yu stick to stockish parts. Once you start "pupming it up", the cost of the Chevy goes up significantly. Also, the Pontiac makes MUCH more low-speed power. That combined with "tall" gears and a "tight" converter makes the car fairly "good" on gas. With the right camming and intake/exhaust, 20 MPG and 350 HP/450 lb. ft. is well within "reach". And that's using an old-fashioned carb and ignition, no computer controls.
I make no secret of it, I FAR prefer the Pontiac. The Chevy does have it's good points, but it's NOT the "giant killer" some believe it to be. Always remember: GTO didn't get its reputation from LOSING to SS396... (:-
