You can also use iTunes match for $25/year. Then you have access to all the music on your computer (up to 20k non iTunes purchases). But I will warn you that if the 3G in your area is slow then it will play choppy if you don't download a couple songs before hand.
A third option is to use Google play. The downside there is the initial upload time of all tour music from your computer to the cloud. And since it plays in Safari it will stop when you leave the browser.