sms website

i want to make a website via which the user wil be able to connect and send sms to mobile phones, single numbers or bulk sms i do not want any sms gateway or any great deal of programming, there is a company that offers me a http api , and i want the whole website to e build on this this is how it words for example we send a simple sms with the http api will we have to call a url of just as the following : [login to view URL];password=xx&from=giannis&to=6941234567&text=testing we just call the above url and an sms with text 'testing' and sender 'giannis' will be sent to the mobile number 6941234567 i think that this is engough so you can give me a quote and a timeframe, if we have a deal i will deliver the complete documentation i want the user to be able to do the following via my website : create contact lists and contact groups send sms to a group, or multiple numbers insert new numbers into a group from a .txt doc buy credits via credit card/paypal/bank transfer (all payments will be done via paypal) i think that this is generally what i need thank you