Finally should i be planning a Tibet trip?

There are a few countries that has always in my mind since young. Japan was one of it and i managed to squeeze my first trip to Japan last year. Next, a Tibet trip that has always been in my mind. This definitely isnt an easy trip and i have been hesitating on the decision if i should go but always fear the altitude sickness that might happen to me there... So this year, i planned 2 trips, one to China Shang-rila, where i can test if i have any altitude sickness, and year end to Myanmar. Myanmar would be a totally adventurous trip since Hollie and me are pretty clueless yet about this country. So if the 2 trips went well, most probably Tibet, along with Kathmandu would be my goal next year! With the various choice from signing a tour package with the local agencies to paying slightly more to join SGtrekker(If i cant find kaki to go with me). Hopefully this come true. But first, think i should start planning the Myanmar trip.