I had your sized tank (a 5' 120). It got small really fast. I ended up upgrading to a 210 so I could keep an emperor angel and some larger fish. You won't be able to keep a mature large angel in that tank.
I think you could keep the puffer, grouper and trigger, but I would substitute another fish for the large angel. Either:
a small tang (e.g. mimic, yellow, tomini, kole);
smaller angel(s) like dwarf, Genicanthus or something from the Chaetodontoplus genus (angels are not beginner fish, IMO);
wrasse - Australian harlequin tuskfish are wonderful fish, if pricey. Very colorful, active, peaceful. I also like the hogfish, like Diana's or Cuban hogfish, which don't get too huge.
Diana's hogfish
a snowflake moray would be fine - make sure the tank is well covered, these are known to be escape artists.
If you have good filtration and plenty of hiding spots, cover, I think you could add 1-2 more fish to the trigger, grouper, puffer, but really not any more. One more would be better - 4 large, high bioload fish in that sized tank is really plenty.
BTW, dogface puffers are available in some really nice color morphs. Look at the black and dalmation dogface puffers from the Solomon Islands.
Also, while picasso triggers are really cool looking, there are some less common triggers from the same genus that are very different and really nice - Assassi, bursa, etc. You could also look at some of the genus Sufflamen triggers. Check out the triggers section on bluezooaquatics and liveaquaria.
Assassi triggerfish
BTW, there are some other nice, smaller groupers to consider as well, unless you have your heart set on a miniatus. For example, miniatus gets 16 inches, leopard hind gets 7: