since your tank is not drilled you need a hang on over flow box as for the rest of your set up its ok. the ehiem can be used along with your return pump if your hellbent on using it.
forgot to add you will need filter pad above your scrubies. scurbies will house your benneficial bacteria to run your biological filtration but you need to actually filter particles out of the water before it so that your bio media isnt constantly clogged up.