Write a Plugin for Wordpress (to extend a existing one)

For our website we need a plugin which does the following task. There is already a Plugin which write input data into the database, do a calculation and generate an output on a new page. Now we want to extend this plugin. To do the following All aspects of the Plugin must be prepared for multilanguage use, right now 3 languages (german, english, spanish) But must be easy to extend for future use of new language. ONLY BID IF YOU ARE ABLE TO DO THE JOB, PROVIDE US WITH YOUR BID WITH WORKING EXAMPLES OF YOUR WORK. WE DELETE BIDS WITH CANNED MESSAGES LIKE "READY TO DO bla bla" STEPS TO DO 1. Generate a Form on existing Page with the following Values Name / Surname (Name is already in Database) Street Address Street Address 2 Zip / Town Country: (detect by IP maybe ?) Email: (is already in the database) Telephone: Radio Button for selecting the Product which is sold (in the moment there is only one, but must be optional to 4 different Product options) Payment Options (Paypal / Sofortüberweisung (german provider) / wire Transfer) Send Button Action after sending the Form 1. ==> write input from the Fields to database ( Name / Surname, Street Address, Street Address 2,Zip / Town ,Country: (detected by IP) ,Email: ,Telephone: ) 2. ==> open selected Payment provider (in combination with s2member plugin) PLUGIN MUST USE FUNCTIONALITY OF S2MEMBER Plugin Please check on API [login to view URL] 3. After Payment -user must be set as paid (in s2member), PLUGIN MUST USE FUNCTIONALITY OF S2MEMBER Plugin Please check on API [login to view URL] 4. Redirect to next page where the User has to answer a list of 75 Questions, which should be devided in several blocks of max 10 Questions. Preferable, the User answers 10 Questions in a Block and click next. While click next the Data till there should be saved in the database so if the User has to stop and want continue later the given Answers are already there. 5. All answers must be written into the database for later usage. [login to view URL] Question : Are you Blond Qid: 1 Answer1: yes Qid:1 Value: A Answer2: no Qid: 1 Value:B etc. 6. After writing Values of questionary to Database, all Value Fields have to be counted and result has to be written to Database f.ex. 12 answers with Value A, 20 answers with Value C, 43 answers with value B = Database A=12 B=43 C=20 7. We provide Questions and Answers in a Goggle Doc File and they have to be adapted. 8. a admin backend for question / Answer management should be provided with a form like this. Language : (preferable in Tabs like qtranslate) Question_id: ____________________________ Question : ______________________________ Answer : _____________________ Value: _________ [x] Answer : _____________________ Value: _________ [x] Answer : _____________________ Value: _________ [x] Answer : _____________________ Value: _________ [x] Answer : _____________________ Value: _________ [x] 8. After writing the data into the database a email must be generated and sent to user and administrator email. All aspects of the Plugin must be prepared for multilanguage use, right now 3 languages (german, english, spanish) But must be easy to extend for future use of new language.