Website form required

1) Input form to append to the value of the input the value from a checkbox - so for example a input textbox allows the user to input text then appends to the end of this the value from a checkbox. (example of this use is when searching for a domain name you select which TLD is required i.e. .co.uk, .com etc. and then enter the domain name so mydomain.com. I only want to allow one checkbox to be selected.
2) I also require a user form that takes a selection and shows another part of the form and captures some input then on form submission posts the data to a Db then redirects to another page.

Please reply and i will provide a more detailed explanation.

* I will also require this to be completed asap so please only respond if you can complete quickly.