Quick cleric domain question

[Chidori]

Hi im trying to find a way to have an human cleric with the planning domain and later take the sovereign speaker prestige class is it possible?

[Troacctid]

Sovereign Speaker requires you to worship the Sovereign Host, which does not offer the Planning domain. If you were in the Forgotten Realms, you could take the Heretic of the Faith feat to swap out one of your domains for one your deity does not offer; however, as Sovereign Speaker is Eberron-specific, I would not expect both options to be available in the same campaign. You could ask your DM, though.

If all you care about is getting Extend Spell as a bonus feat, you could use the Arcane Disciple cleric variant from Dragon #311.

[Chidori]

Thank for the varient and yes it basically for the feat