b&m stands for bargain madness or something. its a really cheap shop. they have them spread out over the UK. i think they have just taken over some cheap home store or something. thats where i got my jars from, they were next to just sealed jars for coffee etc.
i use mason jars 1/2 pint size, they each hold about an 1/2 oz maybe more sometimes.
and burping would still be needed even if you vacuum sealed them. you still have to let the moisture out so that the bud does not mold. you dont want to lose your bud to mold do you.
i got some of the ones with the wire latch and rubber gasket. i like them. everyone was out of mason jars at harvest time so i ordered from crate and barrel. 5 bucks each.