OK, Unfortunately you are already off to a rather bad start. Since the others have expressed their concrens over the cycling of the tank, I will move on to the stocking issues. Proper cycling is the most important part of a new tank. Your fish will not make it reguardless of compatability if the tank is not cycled.
You have too many fish already and many of them are not compatable with each other or for your tank size.
Kenyi and zebras are extremely aggressive and should really not be kept in anything smaller than a 75g 4ft tank.
They (like all Malawi cichlids, and many Tangs and Victorians)are harem breeders. This meens they need to kept in groups of 1 male and 3-5 females of each species. Too few females will cause the males to harass the females mercilessly, possibly to death.
Having lone males is also a recipe for disaster. You need to do either proper breeding groups, or go all male with one fish per species. Single males will fight for rights with the few females that are around, causing the females even more stress and violent, often deadly fights between the males.
Dolphins (Cyrtocara moori) and frontosa need at least a 6ft long tank as they get large and are open water swimmers. Fronts don't usually do well in a community setting with mbunas and once the fronts get big enough they will eat the smaller species. (I have seen a 10" front try to cjhoke down a 4" yellow lab...both fish died).
I would keep the duboisi out as well. Everybody like the little spots, but they lose those as they mature. Adult tropheus are quite beautiful as well, but many people are very disapointed that they loose the dots rather quickly. Tropheus are colony fish and can be very difficult for new cichlid keepers.
Any one of the species you currently have could easily claim the entire tank as his territory and try very hard to kick the rest out. With nowhere to go, the trespassers are often killed when they don't appear to be leaving.
Take a look at the cookie-cutter stocking selections
in the Library section for your size tank (footprint is all that matters with these guys, height is often watsed space). The 29gallon is actually the closest footprint, since a 40g long tank (the next example option is a 4ft long tank with really does improve things alot. The bow in the fron, doesn't add much eith as the "run awway" distance is still only 36".
If you go with a Lake Malawi tank you could probably do two species (4-5 fish per species) of the moderate aggression level species, like Labs or the dwarf species like Ps. saulosi. A very good combination that is both attractive and active in a 42 bow woyuld be Yellow labs and Ps. demasoni (4-5 Labs and 12-14 demasoni)
For some Tang options, you could so some shelldwellers like multies (if you want a colony) or something like a pair of Occies (if you want more personality) and a pair of calvus/comps. Julies can get very, very cranky if they pair up and breed. I had an entire 30g tank (36"x12" footprint) get terrorized by a single pair of julies. All the other fish were chased up to the water line and had to stay behind the filter tube to escape being attacked. They now have their own tank.
Do not feel disheartened by all this. We were all in the exact same place when we strated our cichlid adventure.