A money saving purchase on lighting that I would take a look at are chinese leds. Some of our more advanced reefers here use them for their tanks and apparently they are very nice units, especially for the price. I am most likely going to order 1 of them tomorrow.
New Dimmable 120W Aquarium Coral Reef Fish Tank White Blue LED Light White US | eBay
To get good coverage on a 55g tank I would suggest buying 2 of them. With 2 you will have to run them at low power but you will have the means to grow any light dependent organism you can get your hands on.
That's quite the filter you bought there. I've never seen one quite like that before.
Good choice on sticking with softys for a while. I started up my tank back in april and just now bought my first stony coral. I think it was a good amount of time to let my tank establish itself.
1 word of advice that I wish I had learned before starting up my tank.
Even if you have no fish in your tank be sure to QT your first additions before they go into the DT. I didn't and my DT had to sit fishless for 6 weeks because of ich.