Question: As the title says I am looking for any abilities, spells, enchants, ect that would stack with [haste](http://www.d20pfsrd.com/magic/all-spells/h/haste)/[speed](http://www.d20pfsrd.com/magic-items/magic-weapons/magic-weapon-special-abilities/speed) (Preferably speed). I am attempting to build a character who hits A LOT. I know I have seen something somewhere that stacked with speed but I cannot find it anywhere now.

The build I am attempting will be using multiweapon fighting with a speed enchant on each weapon he uses.

EDIT:

To be more specific I am looking for abilities, spells ect that will not change the character physically and will only use his weapons. 

The answers so far offer good advice but not quite what I am looking for.

YogoZuno is the closest with mentioning the Monk and two weapon fighting tree.

Answer: 
Natural attacks. The multiattack feat, and lots and lots of natural attacks. Each one of them you can get is one more hit per round. If you're combining this with the Aegis lunadir mentioned for 4 arms, you can use the Harness Power Stone customization for metamorphosis, claws of the beast, and bite of the wolf for several natural attacks. Lots of magic items give you another natural attack. Go for the aberrant Aegis archetype for even more natural attacks. You can find even more ways, but this list covers most of the low-hanging fruit.
Weapons and natural attacks work differently as you progress in levels. Where number of attacks will increase with your characters base attack bonus, natural attacks can only be used once per natural and secondary natural weapon. To increase your number of attacks beyond the normal for your base attack bonus you could take an exotic weapon proficiency feat in a double one handed weapon such as the Taiaha (UC: Pg.148) on top of your dual wielding, or simply add on additional natural attacks. 
Which ever you choose to go with (keeping in mind that using a normal attack in the same round as a natural attack will treat all other natural attacks as secondary natural attacks) you will need spells and enchants to up your hit chance. Assuming you take levels in caster for haste, your base attack bonus is going to be lower than usual on top of any penalties you take for making additional attacks with double weapons. I would look into buffs like Good Hope / Heroism if you plan on taking levels in bard. Also grabbing potions of Enlarge Person early on are extremely useful! I did this on my dwarf wielding dual dwarvens, the damage you output with one hit makes up for three.