You could use this setup however it does seem a little dated. I haven't seen a tank in that particular shape in a while. With a 6 gallon tank you actually do not need a protien skimmer. Regular water changes are all that you'll need provided you put in plenty of live rock.
As far as lighting goes you should look into some of the LED
lighting systems Beamworks manufactures. Check on eBay. Seems like I remember a small 9 bulb, 18 watt fixture that might work perfect for your setup. I'll post a link if I'm able to find it.
PS - you might consider moving this thread over to the nano reef section. There a lot of good people of there who would also be willing to chime in with suggestions.