Sleeping bags and down jacket will be provided to you by us. With regards to trekking poles, if you are used to walking with it then take them with you, as you will probably find them useful especially on the way down. They are not essential though and the walk is manageable without them. It is mostly a personal preference. If you prefer to take the poles with you on the trekking then you can either bring your own pole or buy it from numerous options available in Kathmandu itself.
