I mainly agree with Kitru here, but I want to point out that no matter the armour grade, you can make your character look as if wearing light and non-restrictive clothing.
As for species, I would suggest Human, because they have a wide range of customizable looks. Replicating an Echani look should not pose much of a challenge.
For class, I would probably recommend Sentinel (with vibroswords instead of lightsabers), because they don't have a lot of flashy offensive Force powers, plus their fighting style is rather mobile and acrobatic, and is primarily reliant on weapon attacks and kicks. So just spec Ataru and pretend Blade Storm to be an empowered vibrosword slash
EDIT: And yes, I also want a proper martial artist class. No (visible) Force to speak of, minimal to nonexistent tech. High mobility, high control, high avoidance.