2008 or 2015?

Answer:

Since the new version of the standard is already published, I would suggest you to go with the new version. The main reason is you will avoid conducting a transition to the new version which is mandatory until September 2018. This will significantly decrease the cost of maintaining your QMS certificate because you will avoid implementing one version and than making changes to adapt to a new version.

The only reason for implementation of 2008 revision is there is a lot of materials regarding it and consultants are familiar with it so it would be probably easier to implement in, but again you can not avoid making a transition later.

For more information, see:
- ISO 9001:2015 – The benefits of early implementation https://advisera.com/9001academy/blog/2015/09/29/iso-90012015-the-benefits-of-early-implementation/