A ninty gallon is a deep tank...
It all depends on what type of corals you want to keep. PC (power compacts) would keep leathers, shrooms, polyps and some LPS corals. VHO can keep the above named and a few more depending on the amount you use.
If it were my tank, Halides all the way. 2 250w and 2 VHO actinics. That would allow you to keep about any coral and clam you want. Also no need to upgrade from that. If you go with other lights you'll always want more..
Good Luck