im trying to find out what the biggest differences are between the stock suspension and either tein flex and or jic magic 10 way adjustible....which would you go with.

 

The main purpose of springs is to hold up and isolate the body.
Tires represent 85-90% of what is possible in handling whereas suspension changes tend to try to manipulate the other 10-15%.
Really really difficult to improve things by even 2-3% vs oem design.
Don't confuse changes in feel for actual MEASURED improvements in slalom, skid pad, or other common tests.