Plenty of good adice here re: bags. The only advice I can offer is regarding cold and damp. This trek is could be quite cold in Febuary and possibly quite wet - you're going to need plenty of protections for your batteries to prevent losing charge too quickly.
On a practical note - take more clothing than you think you'll need - especially socks. When I was in the Anapurna region in late September a few years ago, I was completely unprepared for just how cold it was going to be. Got stuck for 3 days in heavy snow - and that was only at about 12,000ft. It was fairly unusual weather, and I just didn't have the clothing for it. I was carrying all my own stuff, so I packed fairly light. Big mistake
Because of the delays, my treking permit was about to run out, so I had to cover 25 miles downhill in one day. I could barely walk the next day.
Depite the headaches from thin air, painful blisters, seriously bad knees - constant tiredness, dodgy guts, and endless walking, I'd do it again tomorrow. Seeing Annapurna 1 being lit up at 6am through the clearest air you'll ever see is somethign thats still with me.
Wishing I was going with you