I would of course check with Matia, but I personally cook rice and noodles and such in the Mountain Valley Spring water.  I believe she told me anything sitting and cooking in water should use the special water.  But for steaming, since the foods aren't touching the water, tap water is fine.
As for water containers, I HIGHLY recommend the stainless steel.  I started using these before I started treatment just as a healthy living & environmental choice.  After much research, I'd read enough about plastics to be wary.  Plus, stainless steel containers are certainly cheap and easy, one-time investments, even if it doesn't make much difference in the end.  I use Klean Kanteen, you can find them on the web.  They have zero taste to them.  I got a couple sizes so I always have one with me. And, since it's so important both for treatment and general health to drink enough water a day, but always hard to keep track, these make it easy - I fill my large bottle once in the morning, then just refill my drinking cup throughout the day so I know I'm drinking my daily amount.
Hope this helps!