PROBLEM: big mob textures

Hi! i tried to find a topic like this but i fail, if my problem was solve pls send here link.

I want to make big mob but texture map is too big for 64x32 graphic. Eariel if i tried bigger scale of texture (for normal size mob) i had problem with it: it Just look not right on model, i found solve: use 64x32. So what i have to eo if i want make bigger mob? Im useing techne to modeling.

EDIT: i Google some more and i found information about texture size... It must be just in ratio 2:1 and i can use 128x64 etc., is it correct and it Will solve my problem?