Sweet start to the tank! Should really look natural as the vegetation begins to grow. All you really need to add is time (and your new stock of course).
Looks great! I think time and patience to fill out are all you need at this point.
I too am setting up a 55 gal this week, but, have not purchased anything to decorate with. I'm curious where you purchased your plants (very healthy) and driftwood?
It does look good now, just wait a few weeks and the plants will grow nice and tall. You may want to fit a sponge around the intake of your HOB filters to keep plant leaves from slowing the flow of the filter. It may be an eyesore but eventually the plants will block it from sight and you may be able to find one that is black to match the background.