The most I have seen that I believe to be official is studio statistics compiled by AboutGundamWing.com (where ethnic origin and second set of variances all come from the Gundam Wing Technical Manual or the Sunrise Volume 1 Support Materials, and initial information taken from a translated version of the references sketches available in Gundam Wing: Characters' Collection 2 and verified with a few other translated sources and GundamOfficial.com), a scan from ARTBOOK Mobile Suit Gundam Wing Material Collection Part-1 Sunrise Art Book Series III that tells the stats of him, a 2005 individual art trading card from MegaHouse, an Upper Deck trading card from Series 1 and the back of a shitajiki board.
Studio Statistics:
Trowa Barton
Age: 15?/unknown
Sex: Male
Height: 160 cm
Weight: 44 kg
Eye Color: Dark Green
Hair Color: Mustard Brown / Brown (sources vary)
Ethnic origin: Unknown
Art Book Scan:
Status: MS G-Heavy Arms Pilot.
Age: Unknown.
Race: Unknown.
Sex: Male.
Height: 160cm.
Weight: 44kg.
Eye-color: Dark Green.
Hair-color: Brown.
MegaHouse Trading Card:
Name: TROWA BARTON (To-ro-wa Ba-to-n)
Age: Unknown (Estimated 15)
Height/Weight: 160cm/44kg
Eye Color: Dark Green
Hair Color: Mustard Brown
Human Type: Unknown
Hometown: Unknown (Estimated L3 Colony Group)
Upper Deck Trading Card:
TROWA BARTON
Vital Statistics:
Status: MS Gundam Heavy Arms Pilot
Age: Unknown (Assumed to be 15)
Ethnic Origin: Unknown
Gender: Male
Place of Origin: Unknown (Assumed to be L3 Colony Cluster)
Family: Unknown
Height: 160 cm
Weight: 44 kg
Eye Color: Dark Green
Hair Color: Mustard Brown
Shitajiki board:
Mobile Suits: Gundam Heavyarms.
Pilot: Trowa Barton L-3 Colony.
Data: 03.
Code Name: Trowa Barton.
"I understand danger... After all, I'm used to walking a tightrope..."
ID: Pilot of the MS Gundam Heavyarms.
Age: Unknown (believed to be 15.)
Race: Unknown.
Sex: Male.
Origin: Unknown (believed to be the L3 Colonies.)
Family: Unknown.
Height: 160 cm.
Weight: 44 kg.
Eye Color: Dark Green.
Hair Color: Brown.
Special Characteristics: Wears clown make-up in a circus.
Abilities: He sees himself as a weapon made for fighting and excels in acting power.
Personality: Cool and quiet. His actions sometimes reveal the sadness of one forced to live among people who fight.
Past: Unknown.
Present: On a mission to destroy OZ. He camouflages his Gundam by traveling with a circus.