With a halforc cleric of helm, he won't need any.
The only problem is killing bloody golems before you get the rod of smiting. Its painfully annoying. Iron Golem beat the crap out of the gated in Pit Fiends in a few seconds (shudders).
Cloak of Non-detection is useless, I always get detected just fine with True Sight, which is perhaps why the spell says it will. So, what is the mage going to do while the cleric casts Sanctuary? Its better than invisibility, he can cast some spells and stay hidden.
If your mage can use SPELL TRIGGERS, he has obviously be given the chance to prepare. In that time, the cleric could ALSO prepare by summoning creatures, using Aura of Flaming Death (lots of damage for a mage to absorb for each spell they cast I think), Blade Barrier if your too lazy to use stoneskin, Draw Upon Holy Might (and the other 3 or 4 HUGE bonus spells for clerics combat abilities) and can cast other spells.
Oh, wait, after I surivie your Wiltings, then I pelt you with energy discs and you won't be casting time stop in time. Poor mage.
And just why are melee attacks 'out of the question'? When your stuck with 50% spell failure, your not going to cast many/any spells for awhile. In that time, the cleric laughs as be beats the crap out of you.
The cleric would have put Aura of Flaming Death in place before the spell battle starts. A mage can survive 4 or 5 spells likley before keeling over and dying.
Oh, and I didn't get a reply to using the Antimagic scroll to make the mage unable to use any magic. I think that the cleric is about to beat the crap out of the mage by default at this time.
Yes as many have stated, no class is better than another really. Each has its uses and can beat another in many circumstances. Sometimes, a cleric can kill a mage, and perhaps, maybe, a mage MIGHT be able to hurt a cleric.
JK a mage might be able to kill a cleric some times too.
If things are at low level, the mage is as good as dead. At midlevels, I think the mage would win. At high levels, I think its all circumstance.