This link has been updated and is now in English. There are many good mods, but for many, 5 or 6 volt vaping is the best. From what I have read on here and talking to many vapers, the GG could easily be considered the top of all PV's made. Here is the link that I would suggest you look at:
http://www.ecigarette-mods.com/battery_tube_mods.html