i thought that i would ask you since you know alot about this sort of stuff.
i am making a preworkout supplement of my own so far these are what i am going to include

Creatine Pyruvate
AAKG
Caffeine
citrulline malate
taurine
Vitamin B6
Vitamin B12
Vitamin C
Beta Alanine
BCAA

am i missing anything and what ammounts should i take of each. i weight 168lbs

I assume you are going to bulk?
 
Always state your goal with your question.
 
Food.

Honest.
Get the diet dialed in first!

Multivitamin?  YES!  As important as everything below.
 
Creatine Pyruvate- I prefer Monohydrate and proven effectiveness with value (3-5g daily)
AAKG - Do not take near training, take 2 hours before bed or some time when you have an empty stomach for 90 minutes before or after a meal and not within 4 hours of training.  4-6 grams/day is the minimum effective dose.
Caffeine  - No.  It is a stim and generally anti-anabolic.  save it for cutting.
citrulline malate - with the AAKG (200-1000 mg)
taurine - Why?  You get plenty in your diet generally.
Vitamin B6  - near meals (50 mg)(more is ok)
Vitamin B12 - near meals (50 mg)(more is ok)
Vitamin C  - OK not around training specifically but spread through the day is ok. 500 mg (more is ok)
Beta Alanine - OK  From 3 to 6 grams a day in 400 to 800 mg split doses throughout the day or in a timed release form.
BCAA - OK. Pre / during and even post workout - dose? 1/4 tsp (1.25 g) per 35-40 pounds

 
L-Arganine (4-6 grams) works even more powerfully when L-Citrulline (200-1000g), Vit C (500mg), Vit E (200iu), Folic Acid (400 - 800 mcg) and Alpha Lipoic Acid (10mg) per day are taken as well.  Most of this is covered in your multivitamin or antioxidant.

ive read that taking a gram of vitamin c about an hour before workout can slightly prevent catabolism.

There is still not evidence to that effect in recent studies.
 
The findings I have read are conflicting at best with very little positive effect but more negative effect for immediate training after C intake.
 
I question the way those studies were done, but it bears keeping in mind.
 
C is water soluble acid.  During training we want to avoid acidic conditions to stay anabolic.
 
The body will want to neutralize the acid.