I would get 2 koralia 1400's. Seems like alot, I know, but I think it will be perfect once you find the sweet spot in placing them. I have a 1400 and a 1250 aqueon running in my 90g. I used to have 2 1400's in my 125g so i think its a good fit.
As far as test kits, get the API for the basics like ammonia, ph, nitrite and nitrate. For the more advanced testing like phosphates, calcium and alkalinity and magnesium I use salifert and hanna testers. Red sea also makes some good kits for those.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.