I got both of them from Play Asia, and yes they are both worth it.
Since you've already played EBA, Ouendan 1 will seem a bit unpolished/lacking in features, but the great gameplay is still there. The big things you'll miss are the replay saves and some of the song skips. The high score data isn't as detailed or as accessible either. But the game is still great, and a must own.
And Ouendan 2 has even more good features than EBA does(more skips, the ability to save any 20 replays you want, and an unlockable difficulty mode where the circles vanish earlier before you need to hit them).
As for music, there are songs I like and songs I don't like in all 3. But these games are designed so well that even though I don't like all the songs, I still enjoy playing those levels.