Welcome to the site, tkeyes :)
Yes, we do have a number suppliers that do not require tax ID but this does not make them illegitimate or illegal and unsafe to deal with. Please be assured that the suppliers listed in our directory have been pre-screened to ensure our members that they are safe to deal with.
These suppliers may not require you outright to have a tax ID but you will be asked for one if you are located in the same state as the supplier you are buying from.
Hope this helps. If you have any other concerns please feel free to contact us at email@example.com or simply post it here on the forum.