Lake Malawi is one of the rift lakes in Africa. African cichlids require hard water.
Your tank is a good size, but I'd strongly suggest rethinking your stocking plans as some of these fish should be rehomed.
The acara,pleco, ram, red tail shark, and tiger barbs should be compatible at least on paper. As always, fish have their own personality and sometimes things just don't work out even though they should.
The convicts is a solid maybe. A single convict may work, but even then these are some of the most aggressive fish for their size. They normally do very well with fish larger than them for this reason. Many times they will kill similar sized fish.
A pair of convicts is a different story. They will breed and will terrorize everything.
If you want to keep 1 convict, give it a shot, monitor closely, and step in if needed. This issue is one you may have eventually even if things are OK now.
The African cichlids should be rehomed. They are too aggressive and need hard water as well.
The good thing is that most of your fish will be just fine for the extent of their life right where they are now.