Hi Doug,
Sounds like a good 50th present to yourself - I'm sure you'll have a great time. You're certainly planning well in advance, so you have time to research a little before taking the plunge. If you are sure that its the Nepalese Himalya you want to visit, then I'd suggest you have a peep at
TrekInfo website, and specifically explore their forums (link at the top of their homepage) - lots of first timer questions asked and answered there, and lots of route suggestions. If you fancy looking at the Indian Himalaya, then the
IndiaMike website is very good - once again, their forums are where you'll find the best info. Its also worth perusing the Trekking Company catalogues for ideas - KE Adventure, The Mountain Company, Jagged Globe etc - Google is your friend. As I'm sure you're aware, autumn is peak trekking season in Nepal, so expect the Everest and Annapurna areas to be very busy.
Booking with a UK Agency is easy and hassle-free - but the most expensive way to do it. Using local agencies is cheaper, but takes a day or so to organise in-country, and the quality is a bit of an unknown - from excellent to awful. Pretty much all of the "teahouse" treks in Nepal can easily be done without the need for a guide or porters, if you wish. All have Pros and Cons, discussed ad nauseam in the TekInfo forums. Whichever way you decide to do it, you'll have a wonderful trip.
