there are only a couple of good dramatic monologs that Cleopatra says thorughout the play. Some of them are not monologs as such - there is like one line of text from another character - but i guess you could edit that line out as it doesn't relaly do much to alter the text or anything. i dont think there is actually a scene with cleo on stage on her own - she ususally has another character with her who says one or two lines
with some editing these two would be quiet good
when anthony dies - she talks about his fine roman qualities - the horror of his death etc - done properly it woudl be a veyr moving speech - act iv, scene xiii,
There is the obvious one when she is taking her own life - talking about the anguish that her and anthony have been through etc. Its Act v scene 3, lines 280 to about 320