Just fitted Koni Special Actives on my 280 Sportline 4x4 and - Wow! Its what the car should have been like all along. Only a couple of 100 miles on it since the fit but no more floating and wallowing. It is slightly stiffer over the small slow speed stuff, but not hard but it is SO much better when pushed.
Kept the springs the same, just a damper change. If doing it yourself, and it is straight forward, you will need a few bespoke tools and it is possible to do it without removing the front hubs and driveshafts etc. watch a couple of vids on youtube, just search for Golf Mk7 suspension change 2x4 method. I needed to get a set of euro tri-square bits (12 point bits), a damper 16mm socket with euro blade fit and a suspension spreader bit. the rest was just in my normal tools box.
If in doubt..... do it!