As with any lizard the temperment can change with the lizard... However, I have not heard about any Egyptian that are "aggressive". I have a juvie Egyptian that will get a little overzealous about food, and has accidentally nipped my fingers, but that is largely because I was using hand feeding as an acclimation method.
I would NOT recommend a 4 foot high cage. They are not climbers persay. My juvie likes to climb UP, but likes to FALL down, so anything that is quite that tall would be an issue I think. I have a 4 ft long x 2 ft wide x 2 ft tall cage that I believe will comfortably house the Egyptian for a few years. The species of Egyptian will determine the necessary long term dimenions, since the max size varies pretty wildly between the two.
Egyptians eat a LOT, and get big, but I wouldn't trade mine for the world. 
Elizabeth

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1.0 Mali Uro Archimedes
0.0.1 Egyptian Uro Zuberi Mosca Khu (Mosca)
0.0 Fish
0.1 Sulcata Minnie
1.1 Iguanas Flik and Loki
0.1 Newfoundland Jasmine (RIP)
0.1 Feline Winter
Indiana & Wisconsin