CP will most likely use the 1-2-2 config instead of the 2-2-2 which are only used on domestic routes. I would pick seat 5FG as you'll get served first during meal service. I think CP still serve from back to front. The lav being near the end of the business class cabin is not a big issue as it is not like Y class where tons of people use it. Being in the first row means you don't have a seat in front of you where you can store your things.

Just my thoughts... have a great trip!