Piratecat
Sesquipedalian
Like you, Jester, I think specialty priests were the best thing in 2e... but I must admit, this seems like an awful amount of work. We've handled it in my game and Sagiro's game for letting clerics freely swap PHB spells out of their spell list in exchange for "theme" spells from the Spell Compendium and other sources. This encourages customization with a minimum of work.