From the 3.5 SRD
Hmmm. Size "Large". That'll probably have to carry over or your player/NPC won't really feel like a giant. So make the guy size Large. The base giant abilities are pretty easy to go over: Str 25, Dex 8, Con 19,Int 6, Wis 10, Cha 7 means +14 STR, -2 DEX, +8 CON, -4 INT, +0...