I'm incredibly flattered that you would make a special post just for me. Thank you.
Don't mention it! I'm more flattered by the fact that you're interested in joining my game. I'm sure it will be an interesting game by the current lineup of players I'm looking at (Kalanyr, Lichtenhart hopefully, Hafrogman, and most likely 2 others which I'm unsure of at the moment)
I too share the same nostalgia from the 3rd IR. It was my first real roleplaying experience also and I really had not gotten used to it all even by the end of it, something I regret a bit. I'm glad you're interested in playing a younger version of the God Emperor, and I'm sure we can come to some sort of agreement as to how he can be statted up.
Hrm, as it stands, the standard Paragon template looks to me to be worth approx +14 ECL, however, perhaps we can create a lesser version of the template, call it Exemplar (I think someone else here had the same idea but that was a long time ago), and attempt to split up the Paragon's abilities by about a 3rd to get this template for +5 ECL.
CREATING A EXEMPLAR CREATURE
“Exemplar” is a template that can be added to any creature (referred to hereafter as the base creature).
The base creature’s type remains unchanged. The exemplar creature uses all the base creature’s statistics and special abilities except as noted here.
HD: Exemplar creatures also gain an additional 4 hit points per HD.
Speed: A exemplar creature’s speed remains the same.
AC: Exemplar creatures gain a +4 insight bonus to AC and a +4 luck bonus to AC. They also gain a +3 natural armor bonus (if the creature already has natural armor, use whichever is better).
Attacks: A exemplar creature makes all its attacks with a +7 luck bonus on the attack roll.
Damage: A exemplar creature gains a +7 luck bonus on Damage rolls for all melee and thrown ranged attacks.
Special Attacks: A exemplar creature’s special attacks, if any, all gain a +4 insight bonus, if applicable. The +4 insight bonus may only be applied to a given special ability once.
Spell-Like Abilities (Sp) or Psionics (Sp): If the base creature has spell-like abilities, it gains +5 to its caster level to use those abilities. A exemplar creature also gains the ability to use greater dispel magic, haste, and see invisibility once per day, even if it did not have spell-like abilities before, at 5th caster level (or caster level = to HD, whichever is higher).
Special Qualities: A exemplar creature retains all the special qualities of the base creature and also gains the following.
• Fire and cold resistance 5. If the creature already possesses such resistance, use whichever is better.
• Damage reduction 5/epic. If the creature already possesses Damage reduction, use whichever is better.
• Spell resistance equal to the exemplar creature’s HD +10. If the creature already possesses spell resistance, use whichever is higher.
• Fast healing 5. If the creature already possesses fast healing, use whichever is better.
• A exemplar creature’s natural weapons are treated as epic for the purpose of overcoming damage reduction.
Saves: The exemplar creature gains a +3 insight bonus on all its saving throws.
Abilities: All ability scores are 6 points higher than those of the base creature.
Skills: The exemplar creature gains a +3 competence bonus on all its skill checks.
Feats: Same as the base creature.
Climate/Terrain: Any land and underground.
Organization: Same as the base creature.
Challenge Rating: As base creature +5.
ECL: +5
Treasure: Standard for a creature of the adjusted CR.
Alignment: Same as the base creature.
Advancement: Same as the base creature.
A bit clunky, perhaps, and I'm not sure if its entirely balanced, but that's the general concept I'm thinking-I'll look it over again tonight if you're interested in it. Note that I'm thinking that the bonus to DC and caster level to SA's/Spell-likes will apply to your spellcasting, so your character would suffer less from taking a relatively high ECL template.
About the Mystic Theurge, I'm house ruling it to say that the increased caster levels it gives you only works towards arcane/divine spells gained from a base class, as allowing both it and the Ur Priest combined allows one to achieve 9th level arcane/divine spells before even reaching level 21. I will however, allow the Ur Priest and I can send you the info for the PrC when I get the chance to look it up/type it if you give me an email address.