You can get something like whats in the link below. Id try to have your drains from the tank as straight as possible. The more straight they are as well as your return line(s) the easier everything flows. You can easily modify the sump you have to accommodate the holder or you can with a hole saw cut a hole where your lines are if you want to keep them as is to be able to drop a sock in.
+1 on ditching the bio balls they trap nitrates and gunk that comes from your tank. Filter socks are the key they catch everything down to micron size.
A few things I would change now- theyre gonna a pain in the butt, but I would get it over with now. Your skimmer should really be in the 1st chamber to skim the water and give your fuge(middle chamber) better water quality. Also when it drains into the last chamber it will give you micro bubbles in your tank- if you get it in the first chamber the sponge in the sump will keep micro bubbles from making it to the tank.
Put some more rock in the fuge maybe a few more pieces and then some macro algae- cheato not caleurpa.
Your return line should be larger your going to want way more flow than that pump and small line are going to give you. As well as youre return line should not be clear- it will be a breeding ground for algae to grow in it, if youre going to keep hose for a return line in the end- you should purchase black vinyl hose so your fuge light will not penetrate it.
Theres no need for lights during your cycle- all its going to do is breed algae growth.
Try to bury your rock at least a bit under your sand- should be all the way to the glass so they wont shift and fall if you get any burrowing fish in the future but at least a bit under has to be done.
You want at least enough clearance between the rock and the sides of the tank to be able to clean the glass- you should be able to get a mag float or whatever other scraper you use through.
Also--- sorry to disagree bart but-------NO STARTER FISH!!!!!!!----- Its cruel to do to the fish- you can get the nitrogen cycle going with a little flake food each few days or a raw, CLEANED UNDER RO WATER shrimp from a seafood counter at the grocery store. Plus once you get damsels in your tank you may not be able to get them out and yes theyre pretty blue right now-BUT they are the most aggressive fish you can get almost and will establish their territory as the first fish in and try to kill every other fish you put in. Youll enjoy them for a short period and hate them for years or until they die---which theyre also the hardiest fish you can get and anything that would kill them would have killed everything else in your tank first. Theyre like cockroaches they can survive almost anything.
Best of luck and welcome to the hobby...Heres the link about the sock and holder:
http://www.google.com/products/cata...ct=result&resnum=3&ved=0CCgQ8wIwAg#ps-sellers