True Strike

Magus? Staff Nexus Wizard? (Arcane Thesis)

True Strike Wand

Wand Spamming

https://www.reddit.com/r/Pathfinder2e/comments/zqyy6t/magus_high_quantity_true_strike_casting/

True Strike Staff?

https://www.reddit.com/r/Pathfinder2e/comments/12qfqxb/wizard_op_better_than_fighter/

When to use True Strike - Analysis/Mathematically

https://www.reddit.com/r/Pathfinder2e/comments/uojvuw/when_mathematically_to_use_true_strike_analysis/ https://www.reddit.com/r/Pathfinder2e/comments/mmqlo5/spellcaster_attack_bonus_and_true_strike/

https://paizo.com/threads/rzs436k6?What-to-do-about-True-Strike

Staff of Divination (True Strike Staff) https://2e.aonprd.com/Equipment.aspx?ID=353

https://www.reddit.com/r/Pathfinder2e/comments/d5crhk/i_for_one_welcome_our_staff_wielding_overlords/

Spellstriker Staff (+1 Striking Shifting Staff)

https://www.reddit.com/r/Pathfinder2e/comments/dged7u/can_a_staff_with_a_shifting_rune_can_be_used_to/ https://www.reddit.com/r/Pathfinder2e/comments/jsk7cz/staves_can_no_longer_have_property_runes/

Can you put a Shifting Rune on a Staff of Divination?

No, Magical Staves cannot have property runes.

That said, the Spellstriker Staff was introduced in Treasure Vault, which is effectively a +1 striking shifting staff. This is what you're looking for if you wanted to turn a Staff of Divination into a Bastard Sword so you could wield it in two-hands while casting True Strike.

You can find some heated arguments if Pathfinder should allow this at all and how it works from rules-as-written but I'll try to summarize as best I can. Shifting Runes change the weapon (and therefore, the weapon traits) to a new weapon but it keeps any applicable runes and precious materials. The crux of the argument comes down to what type of trait is the Staff trait? Well, the Staff trait is an Equipment Trait, not a Weapon Trait, so it wouldn't lose that property when it shifts. You wouldn't allow a Shifting Rune to remove the Evil property from a Vampiric Scythe so a Paladin could use it.