correct, individual reflectors is a must, also what are your plans, if you want to keep sps's, put as much light as possible, so my suggestion would be, to half your set up, 2 sets of 36" that way all the bulbs are the same lenght when it comes time to buy new ones, and you get full coverage

I got T5s in both of my tanks, so you can come and check it out for Ideas if you want, there is another maast menber here whom also has nothing but T5s

good luck

Jose