Luggage and bags:
We all took one bag but we traveled light. We werent staying that long and its way too hot and humid to even wear jeans. I survived with bathing suits, shorts and sun dresses
Clothing/Shoes/Weather Gear: I wore flip flops practically the whole time I was here. That and open toe shoes. It was way too hot to wear tennis shoes.
Toiletries and Medical Supplies: Most pharmacy supplies are cheaper here but they may not have what you may need.
Photo Equipment: I didnt check out how much photo equipment was in Guayaquil but usually their technology is alittle behind that of the States. Even during our Lay over through Panama in the duty free shops at the airport it wasnt as cheap as in the States. An Ipod for example was $50 more than in the States.
Camping/Beach/Outdoor Gear: Maybe you should take a hat or something to shield you from the pounding sun.
Miscellaneous: Do not forget the sun block and mosquito repellent. You might also want to bring an umbrella, you can use it to shield you from the sun or to use it when it rains. Although it may rain often it sometimes helps cool off for the heat.
Toiletries and Medical Supplies: You're on the coast and the sun can be a murderer so don't forget your sun cream and your sunglasses!