Integration with Third party tool using Controller or External

gopan

While hitting a url we will get a post data from a third party.Which is the better solution of handling this ,Controller or External.

Is there any other solution for handling this kind of problem?

After getting the data from the third party we are doing some database update and after we have to redirect to a page.

Is it possible to redirect to a page using controller without submitting the form?
We are using Teamsite 6.7.1