I think it would make more sense to remove the Bb and keep C on the first chord and leave the 4 chords like this: https://imgur.com/mGJT4lj
yeah, for that first chord it just depends how dense you wanna make it. which in this case will partially depend on what textures you have. but in general, the Abmaj7 will sound 'dreamy/longing', the Eb/Ab will sound more "shiny", and the Abmaj9 will of course be a hybrid of the two situations