I went to Nepal in 2007 for about a month. I had one of the best times of my life. Loved every minute of it. I went for the month of May and can't even remember it raining...maybe for one day. I didn't do Annapurna, I did the Everest side for 16 days. I didn't get a porter or guide, just a map, but people that I met along the way said their guides were great so it may be an option for you.
If you're bored one day, I have a trip report on my website...not the area you are visiting, but it will give you an idea of what it's like. I also have my gearlist posted there so you can see what I brought.
If you are staying in the teahouses, then you really don't need much camping gear. In fact, if I were to do it again, I would probably just bring a big warm sleeping bag and some essentials. At night, the teahouses will make little fires to keep you warm and if you get too cold, just drape your bag over you. They are nicer inside then you think. Food and water can be purchased, and its not even worth trying to bring your own (IMO) as it is readily available if you stay on the main track. I brought purification tablets as buying purified water becomes expensive after a while.
I'm not sure about the Annapurna side, but on the Everest Trek most days are cut short by the altitude. So, you don't really need to hike for super long periods of time because you actually can't. You'll hit your daily altitude max and have to stop for the night.
I'm excited for you my friend. You will have a good time.