go trekking in Tibet to Everest Base camp this year oct

I am a singapore citizhen who is interested to go trekking in Tibet to Everest Base camp this year oct. I was just back to everst base camp from Nepal. I am wondering is it more difficult to trek to EBC from tibet than Nepal ? It takes how many days to complete the trek and what is the price for two person ?
How is your advice to fly from Singapore to Chengdu or Singapore to Kathmandu ? Tks