According to official strategy guide, it's:

Terra
age 18
height 5'7"
weight 105 lbs

Locke
A 25
H 5'9"
W 147 lbs

Mog
A 11
H 4'
W 94 lbs

Edgar
A 27
H 6'2"
W 169 lbs

Cyan
A 50
H 5'10"
W 158

Sabin
A 27
H 6'3"
W233 lbs

Gau
A 13
H 5'3"
W 169 lbs

Celes
A 18
H 5'9"
W 165 lbs

Setzer
A27
H 5'9"
W 136 lbs

Shadow
A unknown
H 5'10"
W 145 lbs

Relm
A 10
H 5'
W 88 lbs

Strago
A 70
H 4'11"
W 94 lbs

Gogo
A unknown
H 5'5"
W 132 lbs

Umaro
A 4
H 6'10"
W 436 lbs

I'm not positive it's the most authoritative source, but it's probably not a bad bet.