Channelling (Spirit) could work, but it has some baggage that might not be appropriate. Do you envision psychics using focus items and veils?
So I personally would use the Telepathy and Telekinesis custom Powers. They're on the list (https://www.dropbox.com/s/eclun6icxi51vk7/Custom%20Powers%20Master%20List%20%28V3%29.odt?dl=0), and if you head over to the Generic NPC thread you can see my take on some psychics.
EDIT: Scratch what I said about the list; it's not up-to-date. Telepathy and Telekinesis:
TELEPATHY [-2]
Description: For whatever reason, you can read minds and communicate mentally.
Skills Affected: Discipline, Empathy
Effects:
Mind Reading. You may use your Discipline or Empathy skill with a +1 bonus to read people's minds. This functions similarly to the Reading People trapping of Empathy, but unlike that trapping it does not require any kind of personal interaction. It can be used on anyone in your line of sight, is fast enough to be performed within a single exchange in combat, and is defended against with the Discipline skill. Furthermore, you may use your Discipline or Empathy skill with a +1 bonus to defend against attempts to deceive you.
Mental Communication. You may communicate silently with anyone in your line of sight. This renders eavesdropping impossible and bypasses all language barriers. It also allows the transmission of pictures, memories, and other information that cannot easily be put into words. This does not make deception impossible or even noticeably more difficult. You may use this ability to perform maneuvers with your Discipline or Empathy skill.
Weaponized Telepathy [-1]. You may make maneuvers and attacks with your telepathy against anyone in your line of sight. Attacks made this way have no weapon rating, inflict mental stress, and use either the Empathy skill or the Discipline skill. The Discipline skill is used to defend against them. They work by overloading the target's brain with mental signals, causing pain and confusion.
Greater Weaponized Telepathy [-1]. (Requires Weaponized Telepathy) Your telepathic attacks are weapon 2.
Superior Weaponized Telepathy [-1]. (Requires Greater Weaponized Telepathy) Your telepathic attacks are weapon 4.
Compulsive Weaponized Telepathy [-1]. (Requires Weaponized Telepathy) When you take someone out with a telepathic attack, you may compel them to act in accordance with a mental command. Commands made this way cannot be completely out of character for their targets. As a general rule, the limits of this ability are roughly equivalent to those of a successful social attack.
TELEKINESIS [-2]
Description: You can exert physical force with the power of your mind alone.
Skills Affected: Conviction, Discipline
Effects:
Mind Over Matter. Whenever you would use your Might skill, you may use your Conviction skill instead. If you have a Strength Power you may apply its lifting, breaking, and grappling bonuses to your Conviction skill.
Telekinetic Reach. If an action would normally require you to touch something, you can do it from a zone away. If you use this effect to do something which requires good fine motor control, your Discipline restricts whatever skill you use.
Telekinetic Attacks. You may use your Discipline skill to hit people either unarmed or with objects. Attacks made with this effect include stress bonuses from Strength Powers and are treated as ranged attacks for the purpose of selecting defence skills.
Enhanced Telekinesis [-1]. Your Telekinetic Reach extends to everything within your line of sight. In addition, unarmed attacks that you make with this Power are now weapon 2 and may be enhanced with any Natural Weaponry upgrade except for Summoned, Explosive, and Ranged.
Defensive Telekinesis [-1]. You are protected by a shell of telekinetic power. You may use your Discipline skill to defend against physical attacks or to create physical barriers.
Self-Propelling Telekinesis [-1]. (Requires Defensive Telekinesis) Your telekinesis is strong enough to let you carry yourself. This allows you to fly as though you had the Wings power, using Discipline instead of Athletics to move around in the air.