I say just use the chocks with rear wheels under sides of car as backup, and point car downhill when working on the rear. Be sure to use two big wheel chocks and not just a brick or piece of 2x4 wood as a chock. Place both chocks on the downhill side of both front wheels, not on both sides of one front wheel. The chocks mean almost zero chance of car rolling and putting rear wheels under sides of the car mean if it rolls or jackstands fail, the car will fall onto the wheels instead of onto you. Pointing car downhill means if it rolls, it will roll away from you when you're working on the rear (point car uphill when working on the front).
I would feel quite safe on a 5% or ~3° slope driveway using 2 jackstands, 2 wheels chocks, and rear wheels under the side skirts. How steep is your driveway? If you can't measure the angle directly then post the length and drop of the driveway. For example if your driveway is 10m long and drops 1m, that is a 10% or 5.7° slope.
Lowering my car's resale value one track day at a time...