Well, the best option is to go with crafting, and then sort of a heavy medium armour.
Some tips:
You can use Psi Beetle Carpaces as Armour plates in ballistic vests, which makes those the go to armour type for Psykers.
accessorize with a Psi Headband of your choice and whatever boots you can get your hands on.
The boots are really the only actual choice to make, and I recommend going to the wiki and deciding on what you think is a good base material.
