A large tomato clown will be one of the most territorial and agressive fish you will see. I would rocommend against it if you plan to have some smaller doscile fish in your tank. They really do not take well to newer additions once they have established a section of the tank as their turf.
As for humas, I have wanted one forever as well, but from talking to people who have had them, while they are on the less aggressive side as far as triggers go, I was told that they can easily snap as they grow and take out everything. I guess thats the trouble with triggers though.
For your size tank, I would recommend some of the medium to larger sized wrasses.... there are a number of really nice ones that have a lot of character. I have seen in larger tanks with lots of rock work some huge ones, but be advised that most of them will be carniverous, so dont plan any small gobies and what not as hey might be mistaken for food.
There are some really nice books available that have photos of fish, their size categories, heir aggression levels, and what they do and do not get along with. I would buy one of those and go through it page by page looking for things in the size you want, and making sure that their dietary and living space requirements can be met.
If you like to save cash for fish like I do just go read it at Barnes and Noble or Borders, or maybe ask a relative to get one for you from here for an upcoming special occasion.
GL
Just thought of one more thing..... you can get a school of dithering fish to help ease aggression.... many people use green chromis for that purpose. The larger school of fish provides a lot of targets for territory squabbles and makes a larger target for things to pick on than say, a newly added angel. As an added bonus you get a nice schooling effect near the mid to top of your tank, a region normally not enhabited by most fish. The best part is they are only 3 or 4 dollars each, so on a big tank like yours you can afford to get 10 or 15 and let them think that they are still in the ocean with all their buddies.