lights on reef tank

[mycat99]

i have decided to try and do some easy corals after seeing some of the pitures on site and reading .my question is i have a 90 gallon tank with a tunze 9010 that sits in tank .i cut a piece of plexy glass to go around skimmer .if i was to get metal halide would it be to hot and melt the plastic ?or should i use a t5 4 buld set up ?