I also live in CH and looking to certify myself. One of the very best worldwide is ACSM CPT course from the US (study yourself with 3 books)
http://www.acsm.org/get-certified It is the gold standard for personal training certifications and it is in english...i.e: exam is in english when taken here in CH!
Hope this helps. PS: it is a TOUGH course - the hardest one out there and btw, one of the most highly respected qualifications to have as a PT. Best of Luck.