I would wait on the anthias. They have high metabolisms and need to be fed twice a day, whereas the other fish can be fed every other day. Not only will you add bioload with the anthias, but increased feeding will also add a lot more waste to your system. I would wait until your tank is much more established before stressing the system that much.
Of the tangs on your list, I would add the chocolate tang first and separately from the other tangs. It is a much smaller tang than the others and will need to get established before you add larger more aggressive species. Chocolate tangs are most often available as juveniles and imo arrive around 2 1/2 - 3"; but the other acanthurus on your list you can easily get as 5+ inch species. While some might recommend adding all of the acanthurus at the same time, you also need to take size and temperment into consideration. In your case, with the ones you are looking to add, I think I would personally add in the following order (I suspect others may disagree wiht me, so know this is only one opinion):
* Chocolate tang - let it settle in and get established for a few months before adding more
* Zebrasoma tangs (yellow, purple, desjardini - I assume this is what you mean by indian dasani?) - aim to get ones that are close to the size of the chocolate tang (2-3") - getting the smaller sized tangs won't stress your system quite as much, and won't beat up on the chocolate. Adding 3 at once will allow them to establish heirarchy among themselves while giving the established chocolate 3 fish to diversify any aggression rather than have it all targeted at a single fish
* Powder blue tang - expect to need to rearrange rocks and hang mirrors. You really want to get a healthy powder blue (I'd buy from divers den); they are very suseptible to ich under stress and ideally should be fully quarantined (e.g., treated prophyllatically). Aim to get one around 5 or so inches, it will be less prone to being picked on by the other tangs if it is a few inches larger then they are.
* Anthias
* Blonde Naso
* Sohal
* Trigger
The sohal tang will likely be the most aggressive fish in your system and should be the last tang added. I would aim for a 5+ inch species.
Good luck!