Keyword Research Tool

Hello everyone. Is there anyone out there who can build a keyword tool? You know like the one's that is used at ([login to view URL]) & ([login to view URL]). Their api is too expensive so i'd rather have my own custom built keyword tool. It should just be a free tool where my visitors could type in a keyword or term and then get a couple of suggestion of similar keywords / terms. I don't know much about proxies and programming but i need to get explained to me how the tool will generate these keyword suggestions and from where they are scraped. Can this tool be built without paying for proxies etc? Please tell me a little about your earlier experience in this field and also please provide me with some info if you have built webmaster tools before and if so if you can give me an url from where i can check this. And again, I can have a great tool from other companies but i dont want to pay for their api access because i want my own tool that generates these keyword suggestions for free for my customers and also for me Kind Regards Tony