Trekking in Nepal - who has done it and any advice?

[Redliner]

Considering a trip to Nepal either late this year or early next year. Looking at 3 weeks, flying into Bangkok and then taking a helicopter to Kathmandu. We will likely be a group of 8-12 people and right now we are considering a few options: the Annapurna Sanctuary, the Mustang region, and Khaptad National Park. I would personally like to do the Everest Base Camp or Mera Peak, but other members are concerned that those routes will be very busy and they want to try and avoid the crowds.

I'm sure that some of you well travelled CP-ers will have made this trip before, so do you have any recommendations? What should we avoid, and what are the "can't miss" areas? Some members of our group are in their late 50s or early 60's, but all are in excellent physical condition and have lots of experience in the mountains.

Any advice on what gear we should take? I'm assuming water filters, possibly solar battery chargers for camera batteries? Would you recommend trekking poles or are they not really necessary?

Thanks

[Cheese]

I havent done this trek yet, but have 2 groups of friends who did it last year. Both did the base camp hike.
Routes were not busy...both groups are extremely physically fit and both suggested the hike was "extremely" taxing even for them. Lots of verticals and scree slopes. Make sure you are very fit.
They do not have solar power chargers...we actually LOLed about some of the younger people on the trek that had their iPods, etc with them. Id get a camera that uses batteries for that part of the tour, or buy your own solar panel and attach to your backpack.
Water wasn't an issue...they provided fresh water for the group I think I recall them saying.
Lastly...one good friend of ours who went on the first journey caught a bug...it happens a lot because of the food and general environment. He died.
This man ran marathons and triathlons among other things. It doesnt matter your fit if you get hit. Take ALL precautions.