Sorry for the delayed response. Got lost in the shuffle. Smart is currently available on cryptomania. Don't think it is on any of the other major exchanges but I am not to sure of that, haven't bought any in awhile.

But yeah, you would need to exchange Steem or sbd for BTC or eth and use that currency to buy Smart on an exchange. There is a strong $Smart community on Steem, so check them out for additional info