Invoicing application

We need to customize BambooInvoice ([login to view URL]) as per following requirements: 1. TIN Number: Company (who is using this software to create invoices can have multiple TIN numbers). In Utilities add a page to add TIN. Fields State Name & TIN No. List of states should be a drop-down of Indian states. 2. In settings, a) add option to add multiple service tax rates. b) In settings, add options to add multiple VAT rates. 3. On invoice create page, a) add option to select service tax rate. See attachment for example. b) add option to select VAT rate %. See attachment for example. c) add option of percentage selection of amount for vat and service tax (25%,30% and 33% for service tax and 75%,70% & 67% for vat). See attachment for example. d) Tax amount should be calculated using the selections made above. e) Invoice no. should be auto-generated (see example below): First Word in Company Name in settings, e.g for New Design & Arts: NEW Financial Year: for 2012-2013: 12-13 Client Code for Amazing Engineers: AE 7th Invoice to this client (you need to count the invoices in this financial year for this client):07 so invoice number becomes: NEW/12-13/AE/07 f) While creating the invoice, pick the TIN no. applicable to the client using state of the client. 4. On create client screen a) Generate, save and display unique alpha code for each client. Start with two characters. If not unique, add more characters. Take alphabets from client name. For example For Amazing Engineers India Pvt Ltd, possible alpha codes are: AE, AEI, AEIP, AEIPL. If none of these is unique, add alphabets starting with A. For example if AEIPL already exists, try AEIPLA, AEIPLB and so on. b) add a field TIN number for client. c) add drop-down of Indian states in states field. 5. The pdf of the invoice should look like as in attached file. Please let me know time and cost it will take. thanks