I am looking for a spell system (preferably one that can use the existing spell lists) that operates based on Mana/Spell Points rather than the Vancian system. I am already familiar with the Unearthed Arcana one and the one found here. I am also looking for balancing in this system, and unless the system introduces new classes, I would like to stick to core classes.
Psionic Mechanics, Arcane Flavor
You can try a converted psionics spellcasting system, more detail in a full thread here
Quoting the author:
It includes a complete conversion of the psionic base system, feats and fundamental items over to magical terminology, as well as, more importantly, translated classes to utilize the mechanics, and a relatively thorough conversion of the Sorcerer/Wizard, Cleric, Bard, Paladin, Assassin and Blackguard lists over to what 3.5 fans know as psionic mechanics. For the classes presented so far, it should be playable from 1-20.
And here the main difference from this variant from another:
The primary difference between this project and every other spell point variant I have seen is simple - I rewrote the spells so that they take the system into account. No other spell point system I have seen has done this. In addition, this isn't really a new spell point system. This is the well known and researched psionic system, which we all know works. I just added a paint job and a new bell or two.
If you're looking for a Mana magic system, your first try may be the Unearthed Arcana spell points variant (the same one that you mentioned in your question).
The core problem with it is, ahem, wizard. With spell points variant he
- has just a little bit casting capability than a sorcerer.
- has much more versatility.
- still has to memorize spells per day to define his repertoire for the day, so the Vancian magic remains right here.
If wizard could cast anything from his spellbook but had mana on par that of a bard, these problems could be circumvented. I don't say that is an ideal fix, though.
Note (just a nitpick): as written, magic items do not change bonus spell points for high spellcasting attribute.
The second variant you mention is not a complete spellcasting variant in any case - one still have to assign point cost to the actual spells - and is probably designed with creation of the new classes in mind.
You could also try to take Spell-to-power Erudite casting mechanic for wizards.