Assuming its 50/50 split id go age 30 lowest height, just to maximize dex and attribute points. Having said that, 94 dex is not very fast at all. You wont be running away from anyone. Its an average melee warrior build but kind of on the low side for HP. As far as a mage youll have lots of mana, but your spell will be weaker due to the low int max.
Frankly a full Kallard is a better melee fighter and a full Sidoian is a better mage. But if you are dead set on that mix then you'll make it work. Youll be ok at all things but not the best at anything.