you can probably find those small bags online, or look for something like a "store-supply" store, im not sure how to word it, but a store that sells little things that other stores need to operate.
with regards to the dealing, you need to seriously consider this before jumping in. it is a life decision if you fuck it up.
first, check the laws, find out exactly what risk you are taking, then if you still really want to go ahead with this, read
http://dahustla2.tripod.com/index.html
aside from that, personally i would advise that you not deal, it really isnt worth it monetarily unless your growing what your selling (sit down and do the math, then compare it to a real 9-5 job, then factor in the risks of both and the answer should be easy).