The truth is that, if you don't want a melody that just 'tops off" the chords you probably should work out your melody first, and then find chords to it. The reason that most of the pop songs that have been written in the last 40 years have no melody is that they were written chords first(or lyrics first, which leaves you even less room to find a melody).

However, jazz musicians regularly create melodies through improvisation over chord progressions, and you could simply put your chord progression on an endless loop tape and try improvising melodies over it, till you found something that you liked.

Please don't ask me to tell you how to improvise in another post, I could teach you how to do it, and, if I could hear you play, I could give you some tips on how to do it, but it is way to hard to explain here, and even if I could, it would be pretty hard to understand, unless you could do it already, in which case you wouldn't need the explanation--

For all those of you out there who are disdainful of music theory, let this be a wake up call--the whole point of music theory is to lay a foundation that allows you to create music--the more theory you understand, the more creative options that you have!!!!