What are your goals for the tank? Reef? Soft or stonies? Are you looking to keep fish to? Will you be able to keep up with regular water changes?
What size were you thinking?
Are you drawn to the nanos you mentioned because they're all-in-one? or because of their sleak appearance? A standard tank you can get at a pet shop can work just as effectively and look good with some woodwork...
There are some basics to consider:
1. Filtration. Live rock is a staple for any modern day marine tank and should be used for
biological filtration. Then, if you are able to keep up with regular water changes, the use of other filters becomes less important. Not all tanks need protein skimmers to be successful. What you stock your tank with is a factor on filtering as well - in terms of how much filtering you'll need.
2. Lighting. This is dependant on what you want to keep and how deep your tank is. You need less wattage for shallower tanks. You shouldn't skimp on lighting.
3. Water circulation. You need some movement at the surface for oxygen exchange. The amount of movement needed within the tank is dependent on the livestock you want to keep.
