For being that young, that's an awful lot of foods! I wouldn't do a ton of switching around, etc. You'll just end up with a super picky dog who has YOU trained and tons of $$$ wasted on foods that you swear your dog won't touch (take it from someone with experience in that department
)
Between BB and Lotus, I'd pick Lotus. It's a bit more expensive, at least here, but I really like Lotus and their company -- they even have their own cannery and made one after touring other facilities and decided they wanted to make their own. Makes you wonder what the other canneries look like....
My personal fave brands are Champion (Orijen/Acana) and Fromm.
Oh and I also like Petcurean (Go!/Now!).