EBC trip in Sep/Oct 2015

Yes there is no shortage of trekking agencies in Kathmandu. If you like to bargain hunt you could spend a day or two getting the cheapest deal in Thamel on arrival. If you are a well-informed, confident traveller you even hire a guide, or porter-guide on landing at Lukla, provided you are fine with getting that far. And, it is entirely possible to trek without a guide too. They were talking of enforcing the hiring of guides after the latest disaster at Annapurna though, but that could take a while, if ever.

Holy Sherpa Vision Treks & Travel is run by a personal of many years friend Caleb Sherpa. He is the nicest, personable guy that you can learn a lot from too. He can handle anything you may need: hotel bookings, bus and flight tickets, porters, anything really. I have trekked with him on numerous occasions and can vouch for him. When I visit Nepal I usually try and do a trek with him. I see he is offering a home-stay on his website now too. This may be something to consider too, as you don't get a true inside look into Nepal on the main Everest trail. I don't know where he offers these, but I have stayed with him at his parent's home in the southern part of Solu-Khumbu before.
www.holysherpavisiontreks.com/

I have used Makalu Adventure on specialised trips before too, they are not bad:
www.makaluadventure.com/

Dendi Sherpa is one of the mountaineering guides that I have dealt with, if you needed one. I don't know what agency he is officially with currently but he free-lances and I can contact him.

If you prefer a managed trip ex-South Africa then consider Malcolm Pearse's well organised Summit Ventures.

Hope this helps.

I can't really comment on the accuracy of Tripadvisor in this regard - no idea. Trekking and tour agencies in Nepal can unfortunately be "dime a dozen". Some contract the actual work out while organising everything for you, some may have their regular people that they hire, and others may have their own employees. And, you could go with a very reputable company and land up with a guide who doesn't interact with you much. And I have often heard the complaint from tourists in Nepal that their guide basically just tells them where to walk. If possible, get a guide who is a Sherpa - and this does not mean "porter"- the Sherpas are a distinct ethnic group of Tibetan origin and even have their own language - this is their home turf after all. They should be able to give you good cultural insights (not at all meaning that guides from other ethnic groups are not good enough!). You could also check that they are properly registered trekking guides.

Altitude is a really important topic for Nepal that you need to be very informed about. It is probably the single biggest factor in whether your trip will be a success or not. For EBC you are sleeping at very high altitudes, and spending several days at high altitudes, and this is very significant in comparison to Killi, or even doing the Annapurna Circuit.

Briefly, the usual effects are being short of breath, slight headaches and loss of appetite. This is all still relatively OK though it needs to be managed properly. You can also get really funky dreams and then wake up in the middle of the night and not be able to fall asleep again. That 2000m is going to make an enourmous difference - and your body may not always react the same each time. I have had horrible headaches and that yucky feeling even in Namche Bazaar before (which is Berg altitude) - even though Ive been much higher than that.

Hydration is extremely important as is a proper itinerary specific to the region, and knowing how to manage your symptoms. Its a big topic actually. Have a look at this article that I wrote a while ago, might give you some useful pointers:
www.vertical-endeavour.com/blog/102-other-regions/nepal/83-express-route-everest.html