Write some Inventory Management Software

I need a software for Electronic Showroom that can manage sales and customer record, Generate Bills Products Like(TV, Washing Machine, Fridge etc.) Customer Info. 1. Add/Modify Customer Record(Name, Residential Address , Business address, Phone no.), Guarantor Record(Name, Residential Address , Business address, Phone no.) 2. Date of agreement 3. Cash memo No. 4. Product name & Description 5. Salesman 6. Supervisor 7. Total Amount 8. Down Payment 9. Amount Financed 10. Length of contract(in months) 11. Monthly Installment 12. Monthly Installment Date 13. H.P. Agreement 14. Security Document Details 15. Generate Bills etc Payment Record For Each Customer 1. Date 2. Receipt No. 3. Amount Paid by customer 4. Total Amount Due 5. Generate Bills and Total Due and Total Paid amount of All Customers Stock Management (Sales and Purchase) - 1. Add/Modify Products(Name, Reference, Quantity, Price, Description) 2. Add/Modify Brands 3. Total amount paid 4. Total due amount