This is a clinic in Hannover, Germany, where (cosmetic) LL can be done. I don't know much about them, but I have contacted them yesterday because of my recovery problems (especially with bone regeneration), and got a very useful (even if not so much good news) answer from them within hours! So I thought it is worth adding them here.

I checked out the website and apparantly they use ISKD and Precice nail. Lengthening up to 8cm possible. Possible to walk on crutches from day 1 after operation. Walking without crutches possible after complete bone healing. Price for cosmetic LL is quoted at around 50.000€, but only if no serious complications occur.

This is the website (all in German): 
http://www.mh-hannover.de/uch_beinverlaengerungen.html