Take the KYB gas-a-just shocks and throw them away. They might be ok for a heavy off road car, but on the street they are EVIL!
If you're only using dropped spindles, Koni reds should work fine. 80-1787 is the number for BJ Beetles.
If you're going to lower the car by adjusting the beam down, the normal Beetle Koni red is a bit too long and you have to cut the bump stop down in length.
For the rear, because there is a lot of weight back there, it doesn't matter what shock you use, ride will be good. Bilsteins are ajdustable so they might work for you.
I have used stock 944 Koni yellows on the rear of my Beetle. Stiffer than a Red, the ride is still good.