This shouldn’t need any special models. They’re mostly like humans, but they have white hair. Basically the elves of Star Wars (just not short).
Probably with a +2 Dex / -2 Str or +2 Dex / -2 Con adjustment
From the first link:
" The Echani were a near humans species that have silver-white hair and silver eyes, and better natural reflexes then stock humans. They are also a more willful race, though this aspect of their species came more from studious training rather than any inherent racial quality, and have something of a rivalry with Mandalorians."
From the second link:
" The Echani largely eschewed the use of heavy armor, preferring to fight in light armor, whilst they trained in minimal clothing. Their fighting style focused more on agility and movement, and so anything that hampered their freedom of movement would be avoided."