Sorry missed your reply.
Labs and Acei will look really good together...ration of 1 male to 3/4 females applies.
You could try the Ahli, but I think it would limit your other choices a bit.
What about pseudotropheus socolofi...same ration of 1 male to 3/4 females minimum, or iodostropheus sperengae (rusty cichlid)
And then some peacocks...people say don't mix them with Mbuna but I don't accept that this
always applies, and you have a great big tank.
So...e.g 7/8 of the labs, acei and socolofi, some synodontis catfish and some male Peacocks...pick out 8/10 or so that you like, go for different colourations to minimise conspecific aggression...would be a great, colourful tank...use natural looking substrate, or the black stuff...black background & lots of rockwork...I'm jealous
As with any african set-up you would ideally have a Plan B to deal with aggression - sometimes you just get a Peacock with a little too much 'personality' and you have to be willing to remove him from your tank, especially in an all male Peacock setting.