You BF is making a good point and it's advice I was given when I started and have given to others.

I think you can't go wrong with the BBB's OSFM as they are a great workhorse nappy and I still use the same ones on Caleb that I bought when he was 8 weeks old.

I would also be inclined to use either flanny flats or prefolds as you say you are expecting bub to be a decent size. That way you don't have to worry too much about bub either not fitting into the nappies or growing out of them too quickly. I have bought a few nappies second hand for this bub that were hardly worn and some weren't because they were too small for the ladies 10lber. (A gorgeous 10lber I must add as I had a cluck over her when I picked them up from her house).

As Mel said postage can be an issue if you only buy a few every week so you could either start saving up now and buy a bigger package that may give you free postage included or at least save on spending $8 on postage on average for 2 nappies every week or so.