Boo, the Roland chord sequencer is perfect for guys like you..You can lay down your chord changes in real time, then at the end of your chord progressions, push a button and the progression repeats over and over untill you want to close out the song..fills ,variations , breaks,and even changing of the style will not disturb the chord progression..
You can save all the chord progressions[Chord sequences] to disk for quick recalls, if you do not want to record the Chord sequence in real time..