Hi Casper,
My surgeon told me that it really depends on what your eating habits are like and you personal preference I thought the RYN gastric bypass would be best for me as i have around 11 stone to loose. If you do more research on both options you'll come to a decision that suits you best try
BOSPA - The British Obesity Surgery Patient Association it may help with any questions about the procedures.
Hope that helps a little
Vicci xxx