My 190g with three 250w MH's is set up on my main floor in a room that gets some sunlight in the afternoon does not need a chiller. Before my house had AC the tank would get a little on the warm side some days but with AC in the house the temp stays stable. I think you should be ready to get a chiller if need be but I wouldn't spend the money on it just yet.
-Welcome to Canreef, sounds like quite a tank you have there
