I think OT eval is better than nothing, but do fill out the paperwork for the developmental eval, you never know when a last minute cancellation is coming your way. And they should be flattered that you are traveling Internationally.
Anyway, back to OT, do sign up. In advance read a few books so you'll know what to observe and ask about. Read:
The Out-of-Sync Child: Recognizing and Coping with Sensory Processing Disorder, Revised Edition by Carol Kranowitz and Lucy Jane Miller
and to get started now, read:
The Out-of-Sync Child Has Fun, Revised Edition: Activities for Kids with Sensory Processing Disorder by Carol Stock Kranowitz
But those didn't really sound like my child until I read a few of the articles from -
Uniquely Gifted : Identifying and Meeting the Needs of the Twice Exceptional Student (An Avocus Advocacy in Education Title) by Kay Kiesa and Kiesa Kay
Best Wishes,
Grinity