Plan of action,
1) We need dimensions ESPECIALLY depth
2) what corals you plan on keeping, any clams?
3) You getting a chiller?? If not I wouldnt attempt more than 250 JMHO
Heat is an issue on my 200 gallon with 175, I will upgrade to 250's but I am raising my hood and getting new fans!!
250 DE HQI's with lots of VHO
supplementation could be the ticket, BUT I HATE it, when you have to upgrade when you could of got what you wanted to begin with!!
I had 400's on a 90 gallon prop (4X2 and only 18 inches deep) and she not only kept water HOT but I didnt have to turn heat on downstairs in my house till Christmas!!