Noob question: Do I have to use coinbase to puchase ETH or LTC is there anyone else with lower commissions

Just got some LTC off of coinbase with a CC $150 limit but now I have to wait 1 whole entire week to buy more, any other sites I can use to buy with lower comissions and with preferrably use a CC so I can use my 1-2% cashback rewardsThanks guys via /r/altcoin http://ift.tt/2ues6i7