Dude
I would just use a "regular" harness like the black diamond Momemtum AL (14oz's) it heavier, but chances are that if you are new to alpine climbing your probably bringing to much other hardware (biners, pro, slings) the BD harness wieghs only 3 or 4 biners more than the other light harness/thongs. you may as well get something comfortable and you can use the harness for sport and trad rock too.
ya you would still need to untie to get extra pants on and to take a crap. just plan what you are doing and an akward situation will not arise.