I have been thinking about lighting your tank, with the tank being 5' deep i think you will need two 250w metal halides. IMO planting a tank this deep is going to be impossible so i would skip the real plants. Your tank is going to be very top heavy so i would also think about anchoring it to a wall. The weight of this tank IS going to be a issue unless you have a concrete floor.
Metal halides hang above the tank, you wouldn't want to close them in too much as they give off a LOT of heat but you could screen them off.
Over my 180g (680 litre) cichlid tank i had T5 floresent tubes but my tank was only 2' deep.
You could keep real plants with 2x250w MH pendants over the tank, mostly easier, low to mid-light stuff. You can put them in a canopy, you'll just need a few fans to keep it from getting too hot. You could probably keep most any plant you wanted with 2x400w MH.