I've just used Young's cider yeast and didn't really notice any bread like yeastiness at all. It cleared nicely in the fridge and even drinking the yeast at the bottom of the bottle just tasted 'thick'.
A 5 gram packet makes 5 gallons.
__________________ "That's it!, I'm going to Moe's"
I usually made five gallons of Root Beer at a time and followed the recipe on the Hires Root Beer Extract, which if I remember correctly was something like one bottle of extract, five pounds of cane sugar, five gallons of water, one vial of champagne yeast, bottled in champagne bottles and 2-4 weeks to do it's thing.
DO NOT let it ferment beyond a month or two at the most before consumed unless you want to walk into a wall. I forgot one bottle for over six months...WOW was that a surprise!