Not sure what MPK is...but...
There is no "best" class. Each has strengths and weaknesses, and all can effectively solo in the EQ2 world. Here's a basic rundown:
Fighter: Low DPS but can tank well.
Mage: High DPS but weak armor.
Scout: High DPS and medium armor.
Priest: Standard healer.
At level 10 you pick a archtype path to follow, and at level 20 you do it again. There are additional pros/cons for each of these paths.
For example, in the Mage class, you can become a Wizard with high-blasting nukes. Or a Conjurer that summons a pet and casts DoT's
A Paladin can tank well and heal himself, while a Monk is gifted in dodging blows and dealing stunning attacks.
Check out
this link for a more detailed run down of the classes.
It comes down to what you want to play and have fun with.