Dual Advancement Prestige Class for Artificer/Cleric casting

[Yogibear41]

Is there any dual casting prestige class that could advance casting for an Artificer/Cleric Multiclass? 3rd Party/Pathfinder stuff is okay if I can get DM approval.

[Thurbane]

Is there any dual casting prestige class that could advance casting for an Artificer/Cleric Multiclass? 3rd Party/Pathfinder stuff is okay if I can get DM approval.

No official 3.5 I know of, but Troacctid has this: Gestalt Theurge (https://forums.giantitp.com/showthread.php?427306)