I've got a Panasonic Sport, and you are correct: the stock handlebars are 38cm.
A couple weeks ago I updated mine to these:
http://www.niagaracycle.com/product_...ucts_id=407239 I went with 44 cm because I'm broad shouldered, but they offer the same handlebars in other sizes.
Your stem is 25.4 diameter. That's the critical measurement. Most handlebars should fit as long as they use that stem diameter.