Do a Google search for "Butler Parchute".
Call and ask for Manny.
Discuss your questions with him.
He used to monitor the IAC Exploder and offer helpful comments to these
types of questions.

Jay Moreland wrote:
I need advice on a pilot emergency chute. I am only a pilot and know
nothing about parachutes. I need an emergency parachute because I will
be doing aerobatics in a Pitts-like biplane: required by FAA. My weight
is #140. The altitude I will be landing if I am unlucky enough to need
to use the chute is 5400 feet. I am considering purchasing a used
parachute that I would have inspected and re-packed regularly by a
professional Master rigger.

Is buying a 10 year old parachute like a Security, Softie, Strong...etc
going to be significantly less safe than a brand new parachute?
(Assuming it checks out as OK by the Master rigger)

Is there anything to watch out for?

Are there any special tests that I need to have done on a used parachute
to know that it is still safe?

If the red-line on the aircraft is 180kts, should I worry about the
parachute being rated to only 150 knots or should I assume that I will
slow down to terminal velocity in an emergency and will only need the
150 knot capability?

What other considerations should I think of?