Valve cover spacers....
http://www.jegs.com/webapp/wcs/store...47514_-1_11355
I think you made a typo on the open spring pressure.
As far as the Pro-Magnums, if you have the coin to buy 'em, do it. You'll never break 'em, Comp will rebuild 'em if they wear out and they should contribute to lower oil temp and decreased friction to free up some hp in my opinion.