Lusotannan Light Infantry. 6 javelins and an ap

Another one and one of my favorite light units would be the Balearic Light Infantry. 6 javelins, decent armor, an ap sword and cheaper than the above.

The Thracian Peltast. Nuff said

Bosphoran heavy archers. Nice armor, and archer unit with a .225 sword as a secondary.

I like the Massilian Medium Hoplites also, they do a fine job in any Gaul army.