Are you using an aquaclear 50? Not sure what you decided on.
Some other items you may not have gotten: a refractometer to test salinity. You can get one for like $30 and it is WAAAAY more accurate than the cheap $12 swing arms. This is even more important with your tank since it is small, salt levels can change abruptly and you need accuracy.
A mag float for the algae: about $10. It will also wipe off micro bubbles and dirt that may accumulate during your cycle.
Depending on your stock choices you may want to make a screen top, for the jumpers, since gobies and blennies are from my experience jumpers alot of times.
I really can't think of anything else specific that you need, I think you have all the bases covered. lol