NOKIA 5530 XPRESSMUSIC or NOKIA C5-03...? Can't decide....?

Um, neither. You should get the C6-01 instead if you're opting for a Nokia phone as that phone is a pretty decent phone. The 5530 and C5-03 are pretty slow and very crappy (not to mention unreliable). You'll have a pretty horrible experience with those 2 phones (better than the Corby though, but still pretty bad). That's why I suggested the C6-01 which isn't too expensive but works much faster and is capable of dealing with more apps.