Good idea leaving the haps out, its not that they are to boisterous for the fish its more the tank is to small for them add them once you have the bigger tank, if anything a group of trophs in with haps and peacocks may be your prob. Trophs are super hyper and may be to much for your malawis. But, it may work fine, you will just have to keep an eye on them.
You may want to look at mbuna instead of haps/peacocks. Mbuna have a similar temperament as trophs and may fair better. Realistacally if you want peacocks, you could pretty much go with 4 of anything. I have had a few different types in my all male tank over the years and i have found that the described temperament of a fish you can take with a grain of salt, you really won't know how they will behave until they begin to mature. It is best to try and avoid lookalikes i.e. same colour/bodyshape and go with 1 of each type i.e. 1 maleri 1 jacobfribergi, 1 OB etc...