Look at the sticky under Gluten Free brewing, I think I have some links in there where I got my sorghum (5 gallon bucket) from I think Twin Valley Mills. I was able to modify it. There are some other posts in there about other grains as well.
For the mold...I didn't have any problems, I soaked the grains for 8 hours then let them have an air rest and rinsed them as well. I did read something last year about using a diluted bleach solution in the water to soak to keep mold at bay but I didn't want to go down that road...if you are attentive I think you'll be okay.
To date- I still haven't used my malted grains and I don't have any time to malt any more right now, bummer
Anyways, check here