Given the size of your tank, I would suggest keeping the no. of livestock low. I only have ard 4 livestock in my 1 ft tank.
For price of FR, ya can do a search in this forum for the 2nd hand price.
Lastly, i think you need a small wave maker to create some flow.
The brown stuff is algae. wipe it.
Lastly, i would recommend reading up a bit on the net too. Google.