Hi Vina
It's always difficult to say how much money you should take, as some people get through a lot while others hardly buy anything. Most of your meals are included so you won't need much money for food. I would allow about £20-£25 per day for drinks, souvenirs and the odd meal, plus extra if you want to take the Abu Simbel optional excursion.
I would recommend using the local currency Of Egyptian pounds (10 = £1). You may be able to use US dollars sometimes but not always, and you certainly won't get a good exchange rate.
The temperature is likely to be in the mid to high teens - warm but not boiling - so take a good mix of clothing and something warm for the evenings. Remember too that Egypt is an islamic country and it's a good idea to keep your shoulders and legs covered in public places.
There is a swimming pool on the boat so do take your swimwear if you fancy a dip. You won't need to keep shoulders and legs covered by the pool.
Kind regards,
Olly, your editor