As wearable computing is in its very early beginning you should make
various experiments and share them with your peers.
Doing this with an open and versatile OS such as Linux should give you
a lot of fun ( after all, desktop computer is just a plain vanilla
computer), because you play with both the OS and the hardware.
If you are unsure of the technical decisions you are going to make, you
can start with a proven design. On the net you can find the
specifications of some wearable systems thus you will not have to
reinvent the wheel and you will avoid some pitfalls. ( the designs are
sorted by alphabetical order ).