in any pneumatic application, it all depends on what you are trying to do.
there are multiple variations of valves.
I can't list them all and explain them, there is not enough room to post.
to hold a cylinder in place, I typically use double solenoid, blocked center.
you can also use a blocked center with the mid position having the pressure side going to the a & b ports, BUT !! that's very risky. when you loose air pressure, then next time air is applied, the cylinder will be a rocket when it is energized.
as far as the zero energy state of loto, you must do a hazard analysis and see what the risks are. as I said, loosing air pressure to both sides of a cylinder is dangerous when the cylinder has the air reapplied.
james