Why bother?
I'm kinda like Scott, why? I have a parking brake on my Grumman Tiger that I fly while building the 7A, and have never used it in the ten years or so that I have owned it. I remember reading about at least one instance where a hydraulic parking valve was closed when the aircraft was parked after a high altitude flight early in the day. The afternoon heat expanded the fluid enough so that the overpressure damaged the lines or piston seals, don't remember which. If you use many airports where you park on an FBO's ramp, they frequently want to be able to reposition your plane while you're gone, and ask you to make sure you leave the brake off. I don't plan to bother with them, just to carry some lightweight chocks. Gotta have them for OSH anyway. Reminds me, gotta go get my tiedowns finished and loaded in the plane.