I'm in the US as well, so I understand your pain. I think you're asking how to get access to a wide range of coins and not just BTC, ETH, and LTC that Coinbase offers. Right now, your only real way to do this is to purchase coin from Coinbase and then send it to your desired exchange. Then use those to purchase the coin you really want. Since most exchanges leverage BTC as the primary currency, it'd make sense to purchase BTC and then send it to the exchange. As for exchanges, Bittrex is a good one, but others will comment on the many others that are out there.
Yes exactly what I was looking for. I will buy BTC and go about it that way. Does bittrex hold your wallet like coinbase?