Countering a specific, known threat as a high level Tier 1 spellcaster is usually easy. This is no exception.
Even without appropriate tactics as suggested by Brian Ballsun-Stanton, there is no reason an epic-level Cleric shouldn't be able to just straight-out tank a pair of mundane warriors.
Fighter incoming? Beat him at his game.
You may have heard that "AC doesn't scale as fast as attack bonuses". Well, that applies to muggles, an epic Cleric really doesn't care.
For instance, the Cleric could have the following:
- Epic Mage Armor. You didn't want the Cleric to have custom epic spells, but this one is stock. If you don't want to spend one of your precious Epic feats on stock Epic Spellcasting, just go with some cheap bracers of armor and make up the difference elsewhere.
- Monk's Belt. I assume the Cleric's Wisdom now cancels out the Fighter's Strength.
- An Animated Shield is cheap.
- Add Magic Vestment to your shield for an instant +5.
Just keep going (Ring of Protection, an Ioun stone, Amulet of Natural Armor if you can combine it with your Periapt of Wisdom) until the desired level of protection is reached. If you don't want the Fighter to hit you, the Fighter just won't.
If you go the AC-pumping route, I'd say the biggest source of concern should be that it makes the mundane party members useless and boring. Don't overdo it.
Sneak attack damage? Fortification.
You may still be scared of a Rogue popping out of some shadow and touch-attack stabbing you in a kidney. An armor or shield of Heavy Fortification means the Rogue's trick doesn't work. At all. No save.
Greater Dispel Magic? There's a thing for that.
Afraid of some uppity mage coming around and target-dispelling a critical buff? You should be, even with your caster level advantage. Which is why I never leave home at high levels without at least one Ring of Counterspells with Greater Dispel Magic in it. (Or a non-core improvement, ahem.)
Regardless, you probably want to have your buffs cast with an active Bead of Karma. That gives the buffs a Dispel DC of at least 38 (11 + CL (23+4)), hard to beat in core with just Greater Dispel Magic (capping at +20).
Just hope they don't think of bringing Disjunction!
Contingency is very good.
You have a Contingency up and running (it didn't get dispelled, see above). In core, a Heal is probably as good as you're going to get. Make sure it is timed (that is, phrased) well!
You might be able to make the attacks exceedingly unlikely to hit by using it to (further) juice up your AC. If you key it to Polymorph (beware of unusable equipment, do your math first!), you could look for a form with high natural armor as the least of its tricks.
Make sure Time Stop goes off.
If you get a Time Stop, the Cleric likely has enough time to get up enough short-duration buffs to survive most things. I consider Spell Stowaway keyed to Time Stop a worthy candidate for an Epic feat.
Now what?
You have done your homework, and have an invulnerable murderous machine of a Cleric. Just make sure your players do have a way of winning. In my experience, high level PCs usually do, but be careful.
For the bard interested in metamagic, metamagic song (races of stone) allows bardic music uses in lieu of higher spell levels. Also significant melodic casting, which allows casting while singing.
Looking at the bard's handbook, extend spell and captivating melody are good bets, as buffs and illusions are part of your stock in trade.
Unfortunately, that's about the extent of the things, and captivating melody is an even bet for someone going into sublime chord.
If you hadn't already started, I would have recommended bardic knack and jack of all trades into knowledge devotion, but that's a bit much to swallow mid-game.
Best Answer
The creator of an item need not have or obtain all of the feats and materials required to make the item alone. If I were you, I would apply that same logic to crafting a construct. Simply have the player in question hire an NPC to assist him in the Golem creation process who has the Create Magical Arms and Armor feat. Both the PC and NPC should have the Craft Construct feat, granted to them by your DM fiat. Make sure to include language such that they can only actually use Craft Construct together when both of them are present (or perhaps, by a different partner who fulfills the same requirement: access to Craft Construct through whichever co-requisite of Craft Construct that they don't have). Also, instead of having the PC hire this NPC, you could make it a plot hook and have the players go on a quest where they rescue the NPC in question. It could even be non-humanoid or extraplanar. There are a lot of options to flavor it toward your specific campaign and game world.