The answer was to simply use existing spells as many have done in the past.
Voila. Nothing over-complicated and it has what I am looking for in my games: close enough to the arch-typical medium of fiction and lore, holding seances and using their powers to speak with the dead and other tricks without writing up a whole new bunch of powers and abilities.
The spell-like abilities function exactly as the written spells for range, duration, etc unless noted otherwise.
As written it's a template for my game. Want some variety or tailor it to your setting? Swap out available Powers/Spells for new ones.
Here we go.
Prime Requ: Wis
Exp: As Magic User
HD: 1d6, +1 after ninth level
Save: as Magic User
Attack: As Magic User
Weapons: Any one-handed melee, ranged weapons.
Armor: Any non-metal.
Contact Spirit (1/day/3 levels)
Nearly identical to Speak With Dead (Swords & Wizardry) although no corpse is necessary nor roll required. The Spiritualist must know the name of the deceased however.
The Spiritualist is limited to how long the spirit has been deceased; this time is extended with practice and skill til there is no limit.
Years Deceased (Spiritualist Level): 10 years (1-5th level), 20 years (6-10th level), 40 years (11-15th level), 80+ years (15th level and higher.)
The contact takes 2d6 +6 minutes of concentration and is automatic in most situations. An object the deceased had a close connection to in life will reduce this time by 1d4 minutes. Those participating in a seance will also lessen the time required (minus 1 minute per person/max of -5 minutes) IF they concentrate. If one of the participates is horsing around, incredibly skeptical, etc the DM can rule there is no reduced time or even call for a Saving Throw (vs Spells) to contact the spirit through the interferance. If the Spiritualist is attempting it alone and there is a high level of noise, interferance, etc the DM can call for a Saving Throw for success as well.
Astral Form (as per the spell 1/day)
The Spiritualist may concentrate and project his astral form from his body. He can do this for ten minutes per level.
He can travel anywhere in the world with a thought, as long as the place is not warded with magic circles, protecton spells, and other impediments as decided by the DM. While in this form he is invisible and intangable. The Spiritualist's astral form can be sensed with Detect Good/Evil and been seen with Detect Invisibility and other such spells and abilities. A Dispel Magic will send the Spiritualist back to his body instantly if he fails a Saving Throw.
Spiritualist Powers (Identical to spells)
Level One: Pick two. Useable 1/day.
At Level Two, Four, Six etc pick a new Power or increase a current one by one use per day (up to a maximum of 3/day.)
There are five Power Levels. Each are availble at certain Character Levels.
Character Level: Available Power Level
1-5: PL I
11-15: PL III
16-20: PL IV
Power Level I
Detect Evil (Magic user version)
Locate Object (Cleric version)
Protection from Evil
Power Level II
Power Level III
Protection from Evil 10'
Power Lever IV