If you're in it for the long haul, you can create monk who masters ALL SIX fighting styles (counting Mighty Works twice) in just 19 levels. To do this, you have to plan out all 19 levels and what feats you're going to take, because you literally do not have a single feat to spare, and must be sure to take the proper prerequisites.
You need 6 levels of monk, 9 levels of Shintao monk PrC, 2 levels of fighter and 2 levels of psychic warrior. You have to be Lawful Good to qualify for Shintao monk. You ultimately need Str 15+, Dex 15+, Wis 17+ and Cha 13+ to get all the feats. This is possible with a 28-point buy, and appropriate level bonuses, if you take an 8 in Int or Con. You also have to be human, for the bonus human feat (and if monk is your favored class, you do not take any XP hits due to multiclassing). You need at least 3 levels of monk to classify for Shintao monk, and the other 3 levels of monk are to get Improved Trip without having the Expertise feat (remember, feats are at a premium with this character).
The bonus feats have to be chosen very carefully. Only a few of the martial arts feats can be taken as fighter or psychic warrior bonus feats. And you have to choose the Shintao monk bonus feats carefully, too. The feats that cannot be taken as fighter or Shintao bonus feats you have to take with your level feats.
Mighty Works Mastery I is possibly the best style to master first, since it can be mastered by a low level character and the +2 AC bonus is most helpful at low levels. Meditation of War Mastery may have to come last, given the high Wis requirements.
Assuming you take your 20th level as Shintao monk (which is your best choice for this character), you compare quite well with a Monk L20. In exchange for the extra feats you gained as a fighter and psychic warrior, your UBAB is a little worse +15/+8/+5/+2 instead of +15/+12/+9/+6/+3, AC Bonus is +3 instead of +4, and Unarmored speed is 80 ft. instead of 90 ft. Unarmed damage is still 1d20 (at level 20). Saves are +16/+10/+10 instead of +12/+12/+12. With the right magic items, this character could be the ultimate D&D martial arts character (although you might still get your butt kicked by a Fighter L20).
