info or sale

[kgb]

hey guys my friends just started there tank today. it is a 45 gallon tank with a 4 to 5 inch sand bed and 55 pounds of rock (very nice with coralline algea) with 3 power heads (197 gal/h each).
i am just wondering what the best protien skimmer for the job would be?
does any one have one for sale or know a cheap place to buy one would be ? also theye prefer not to have a hang on (i dont know if this is possible )