I'm looking into going on a trek with my 16 year old daughter in Sept/Oct.

1) I'm debating between the Annapurna Circuit, the Annapurna Base Camp or the Langtang area trek. I prefer the Annapurna circuit (for diversity of views, nearness to the high peaks etc..), but am wondering about the difficulty compared to the other treks (I'm 45 and not as fit as I'd like). Are the other easier/harder?

2) Seeing as we will be two women trekking alone, is it recommended to take a guide/porter? For safety? or to help carry the load? or keep us from getting lost? I'd rather travel independently to lower expenses and also to set my own timetable - we might like to take it slower, stay longer in each place - but not at the expense of our safety.

3) Other dangers - I'm not afraid of heights, as long as I am on wide enough path (one with some room for error). I'm a little worried about high cliff paths - I think I read somewhere about one in the Pisang area?? - are there any that you know of in any of these treks?