I have a planted sand-bottomed 130 with Oscars and a JD in it now. I have kept Texas & Green Terrors as well. So much of their personality has to do with the individual fish and how they are introduced to the tank.
These are not scientifically demonstrable but I have tested all these concepts many times. While there are no guarantees there are a couple things you can do to improve your odds of keeping all you want to keep in one tank.
1. The tank is large enough to house them all.
2. Good water quality keeps fish more peaceful, or maybe bad water quality makes them more irritable. Either way, good water = more peace.
3. Fish have a funny way of learning. The order in which you introduce your fish makes a huge difference. The most docile must be the largest before you put in the next most aggressive. Those more aggressive fish must be larger than the most aggressive fish. It is possible for everyone to be happy this way. Fish see anything they can fit in their mouths as food. If you have a large (6"+) kissing gourami and a 2" Oscar, the Oscar will outgrow the gourami but probably never figure out that the goruami is not the boss. The Oscars will always remember that the Gourami is too big to eat even if the Oscar reaches 14".
4. A backup Plan: You are lucky enough to have enough tanks where you can shuffle the worst offenders to live with larger fish or to take them back to the LFS as you need to. I don't think I have ever had to take a cichlid back.
There are no guarantees but it is certainly possible for all those on your list to get along. The one exception is that if anyone ever decides he/she is going to build a nest. Mating cichlids will fight anyone no matter the size. I had a pair of convicts that owned 3/4 of a 55g and kept everyone else bunched in the far corner (for a week until I moved them to a small indoor pond).
Anyway, Good Luck finding a home. It sounds like you are moving in with the gf for the first time since you mention your place and her place and now her opinion on the tanks seems to matter in a way that suggests moving in together. Have fun with that. I hope you have a wonderful time together.
This is my 135g planted Oscar tank with sand substrate. The tank is 6' across.