Problem with that of course is unless there's ambi, it's a -7 attack for each lance compared to Holy Scourge's +3 attack. So a -10 attack difference, with 20 Astral Pearls v. 5 Fire Gems. So It's not as effective. Course there is a +2 damage for the lance over the scourge, but it's a minor +8 damage total. So averaging 126 damage (including quickness) compared to 118 damage, assuming all attacks hit. The problem is, Golems start with 8 attack base and -5 attack just doesn't help, I mean 2 attack? So if you can get a F1 mage (by any means, I don't know, wish or summons, do it. Buy them from someone).
Actually, I noticed a small error (or maybe just a typo) with your calculations ((25+4)x2), so I'll go over them all over again. As for other items besides these weapons, I'd put on a quickness item most definitely, and extra strength/attack skill items (and a flying or berserk item if you can fit it in) to make the golem an effective anti-tart. In terms of non-uniques, the only ones that'll really help you are Horned Helm and Spirit Helm (both for damage), as we're only concerned about doing maximum damage in one turn, and MR generally isn't an issue when countering tarts (and fear will do nothing). With boots I would go with either Flying Shoes or Giant Strength (+5 str) (with flying especially good if you are going to disrupt their buffing cycle). With armor I would go with Jade Armor for your quickness, and for items I would go with Bear Claw Talisman, Lychantropos' amulet, Girdle of Might, Burning Pearl, Ring of the Warrior, and Stone Bird (and maybe , with the first three for extra strength and the fourth and fifth if you want extra attack (you probably do, since Golems have horrible attack to begin with). Your Golem then can get a max of +14 strength (boots, Bear Claw, and Lychantrops', not including berserk strength) or +9 attack +5 strength, not including special effects (berserk, lightning bolt, Gore, +4 attacks from Stone Bird and +3 attack, +3 defense from quickness).
Flambeau
+4 attack, +2 defense, 13 (AP) damage, fire on target, 15 Fire Gems (11 Gems with Hammer)
If all hits (with quickness), ((25+13)x3-28/2)x2=200 damage+fire (not sure how much that is though, and it depends on fire resistance)
So your golem can have (quickness already factored in):
15-24 attack, 10 defense, 25-39 strength, lightning, gore, 4 attacks, berserk, flying, FR (not relevant), morale, and 200+ damage (with strength bonuses factored in, 284 damage, not including other bonuses)
Holy Scourge
+3 attack, -2 defense, 4 damage, x2 attacks, 5 Fire Gems (3 with Hammer)
If all hits (with quickness), ((25+4)x3-28)x4=236 damage
So your golem can have (quickness already factored in):
14-23 attack, 6 defense, 25-39 strength, lightning, gore, 4 attacks, berserk, flying, FR (not relevant), morale, and 236+ damage (with strength bonuses factored in, 404 (!) damage, not including other bonuses)
Dual-Wielded Herald Lances
-7 attack (ouch), +2 defense, 6 damage, x2 attacks, 20 Astral Pearls (14 with hammers)
If all hits (with quickness), ((25+6)x3-28)x4=260 damage
So your golem can have (quickness already factored in):
4-13 attack, 10 defense, 25-39 strength, lightning, gore, 4 attacks, berserk, flying, FR (not relevant), morale, standard effect, and 260+ damage (with strength bonuses factored in, 428 (!) damage, not including other bonuses)
So yeah. Get a fire mage if you can, because two Herald Lances don't quite cut it because of the loss of attack. Keep in mind all of these damage calculations are based on ALL of the attacks hitting, so you might want to ensure that happens, and it's based on a 28 Prot Tart (which Max previously used), without other bonuses.
EDIT: The same basic item set (minus the weapons) can be applied to Living Statues. As I'm running under the assumption Living Statues are magical (I haven't been corrected if I'm wrong yet), use Moon Blades (x2 attack against Magic Beings) or Elf Banes (MR check for auto-death).