For a 41 gallon all those previously mentioned faish are far too large. A green terror canpotentially be a large 10" monster, requiring a tank of 60 gallons minimum, the corner tanks arnt really adeuate for the larger cichlids due to the shorter lenght and they're increased hight which is th generall corner tank. In a 41 gallon the largest cichlids which you you could possibly keep are discus, But considering you are a begginer, i would advise against this.
A member of the archocentrsu such as the archocentrus centratchus is a larger (7" male 5" female) are are a highly attractive membe of the cichlids. Un your tank you are looking for a fish which grows to about 7 - 8" maximum. The list of cichlids which you have just given just grow too large....
Dan