You could set up Windower's Spellcast plugin to probably do this for you. For example, you could have it macro in until a certain % of your HP has been consumed or until your TP is 100. Whichever is first. It's not that terrible of an idea if you have it done automatically. If you do this manually in anyway its a headache, and you'll feel retarded after about an hour.
I personally have Spellcast do lots of strange things for me such as macro in Amardillo pants for Amnesia and macro back in my standard piece when it wears.
You'd want your XML to include parameters like
Code:
<if TPLT="100">
<if HPGT="76">
<action Type="Equip">
<neck>Berserker's Torque</neck>
</action>
</if>
<elseif HPLT="76">
<action Type="Equip">
<neck>Fortitude Torque</neck>
</action>
</elseif>
<else>
<action Type="Equip">
<neck>Fortitude Torque</neck>
</action>
</else>
</if>
Keep in mind I'm sorta just winging this. You actually gotta do some work to set this up. No, I really wouldn't have time to do it for you, so please don't ask. I'm surprised I took the time to type all that. Looking at it now, I could definitely condense it even more.
Because you don't want to wear this longer than you have to, I'd also suggest setting it up to require you to be engaged in battle. If you go about it just right, you could probably get by with a Regen 2 or a Regen III, providing you aren't taking any damage. If you keep the HP% siphon limit above 75%, your HP will stay white unless you take damage from directly getting attacked. This should prevent your mages from being annoyed. However, if you are "just above" yellow, then they probably won't cure you as long as your HP is white, so you migth want to set it to 74% to force them to have an interest in giving you enough HP to siphon out for more TP.