Hello,
There are a few different ones but it would depend on what you are going to be using the for. Hope the info below helps.
The 53167 are the ergonomic ones the handles are 2K with rugged rubber and plastic outside with a soft core so it forms to your hand. They come with hex bolster and added hole for hanging or using a lever bar. These are my favorite.
The 53521 have a 2k handle with rugged rubber and plastic but these have a ********* and no bolsters but has the holes in the handles.
The 50707 is like the 53521 except it has no hole in the handle and has added hex bolster also a steel end cap for hammering.
If you didn't like the rubber handle you can always go with the 200 series which is hard plastic and also there is the wood handles. Lastly the cheaper 800 series these ones have nickle plated shafts and not chrome like all the other felo models.
You can see all of these at the links below and they are all in stock.
http://www.german-hand-tools.com/Felo-screwdrivers.html
http://www.german-hand-tools.com/Felo-screwdrivers2.html