Trust me I'm one of the biggest SG fanboy's in this forum (yes, I'm sure there's a bigger one). Apophis is...well...a little fruity, let's say. His outfits are usually more lavish than queen Amidala. And thats not exagerrating.
The whole story with Egypt is that many, if not all ancient gods (Egyptian, Greek/Roman, and even a Chinese emperor) were actually Goa'Uld, little snake thingy's that burrow into your spine, attach to your brain stem, and take over your body. The effects are a deep voice, an ego the size of Alaska, and regeneration from death w/ a sarcophagus (healing coffin thingy). The Goa'Uld steal technology and used human slaves back in 4000 BC to build pyramids as their landing pads. Raa was the first of these encountered and was in the Stargate movie. Then came Apophis, then Hathor, and eventually people like Anubis, Osiris, Baal, and Cronus. SG-1 has been responsible (directly or indirectly) for the deaths of over 10 system lords, the loose coalition of Goa'Uld.
The little grey Roswell aliens are Asgard, the most kick ass little guys in the series. The main contact guy is Thor, and other's known are Freyr and Loki. Obviously they take on Norse personas.
And did anyone listen to me? They film the desert shots in a big, fat ass studio.