I have played a monk before and enjoyed it but I was thinking of playing a character who's more of a brawler than a mystic martial artist. I know there are some options in the barbarian class but what else is there in the game?
As a supplementary question, is there any point in making an unarmed combatant character of this sort or are they likely to be outclassed by the, er, classes that do use weapons?
If you have the Dreamscarred Press psionics books for pathfinder, take a look at a Psion with the Egoist specialty, and the Metamorph prestige class at lvl6. Take every power in the Metamorphosis line as early as possible, and spend nearly all the rest of your powers known on other combat buffs. For feats, start with Overchannel, then take anything that boosts your natural attacks. You're not proficient in armor, but you don't have armor-derived spell failure either, so start with MW leather, and upgrade when you can to mithril chain shirt, but don't wear anything with a check penalty, you can't afford the loss of attack bonus.
I'm running such a character now, and he makes for an unarmed brawler with very much the same mechanical feel as a monk, but much stronger to carry your own weight and appease the optimizers in the group. Mine is fluffed to emphasize the mystical aspects, but fluffing in the other direction should be easy enough. You'll not want the scouting secondary focus my guy has, since that depends heavily on using metamorph to become very small, and will probably want to avoid any of metamorph's size-change options, which can be good in certain fights, but the main metamorph options you want are the natural attacks (go for slam, a body slam doesn't tie up your arms if you decide to carry a mithril buckler or keep a ranged weapon at the ready) and fast healing. Both of those, and most of the other metamorph options that you'll want to use often, are easy to justify non-mystically (the Barbarian can get variations of most of them), and the shape-changing effect's blatant mysticality can be easily averted by always choosing your own natural appearance for the shift.
There are 4 classes that have any basis in unarmed combat. These are the:
If the brawler isn't for you, there is a monk archetype(Martial Artist) that has fewer 'mystically' themed choices and more 'martially' themed choices which might be more what you are looking for. It also can be any alignment rather than must be Lawful.
That said, you can build viable(if complicated) builds for unarmed combatant(The barbarian with Brutal Pugilist stacked with the Invulnerable Rager is decent), but as a general rule, most unarmed that aren't monks or brawlers are going to have a difficult time.
You could always refluff monk. You enjoyed playing one before, so why not play one again, this time with more brawling? Rename odd abilities Still Mind becomes Raging Mind, for the same effects. Purity of Body becomes Hardy Body, for the same effects. Diamond Body becomes Iron Guts, for the same effect. Rename the Ki Pool as the Rage Pool, with the same effects (Except it refreshes after 8 hours or rest or inebriation.) Continue as needed. This results in a character that you already know you enjoy mechanical, with a very different aesthetic. (And is really easy to do!) I would recommend changing the alignment restriction- Lawful may not fit the character you have in mind. If needed, change other abilities to match this. (I.E. at tenth level, unarmed attacks count as chaotic weapons.)
