My Requirenment

A company name "ABC Enterprice" .
They need a one application for his company so they are define some information regarding his requirement
We need :::

#Supplier(Company) info
#Customer info
#Staff info
    #manager
    #accountant
    #salesman
#Vihicle info>>>
#Product with pricelist info like Biscuit, weffer etc
    Unit of Measure:
        pieces
        gram

Sales>>>>>>>>>>>>>>stock--
Purchase>>>>>>>>>>>stock++
Stock >>>>>>>Maintain

Report>>>>
    area wise selling
    item wise selling
    supplier wise
    price wise
    customer wise
    salesman wise
    period wise(day, week, month, year)

#To maintain which salesman loaded goods in which rikshow
#To maintain howmuch goods loaded which salesman and which area
#TO maintain howmany payment have cash or credit or cheque
#To maintain particular customer for credit limit

So,Please inform me how we customize this requirement...please comment..