seeking guidance from all the MH users out there

[Aquattro]

For a 36" tank, a single MH is pushing it unless you get a great reflector and hang it higher. 12" would be good, but at that height, I'd go 400w (personal taste). I'm currently building a floating canopy/light box that houses my gear, using a flat panel mount to "float" it.
Adding supplemental T5 would also work well.