Firstly you need to really work out your observing and photographic criteria. Do you want to see the people on the moutainface as small moving 'blobs' or do you want to see more, such as the climber with some surrounding detail or right in close for clothing or facial detail etc?
What you decide from the question above will have enormous rammifcations on the type of scope required as well as it's optical quality and hence cost.
Secondly you need to consider the mounting for the telescope, do you require it to work from a base camp location or are you intending to use it on a mountainside, etc? Also what weather conditions will you be operating the telescope under? Storms? Wind conditions? How critical is portability and weight.
Once you have evaluated the above get back to the thread with some fairly definite answers and accurate help will be forthcoming.