Add a new feature in a Joomla component

WE have created our own component, that we been using for sometime now. The component allow us to take an RSS feed and pull the content in that RSS feed in to our site, and then we store the content items we are interested in, into the joomla content component. The area we want to make a change to, is the edit feed area of the component - see screen shot attached. As seen on the screenshot, I have divided the screenshot into two colors - the pink color symbolize fix field information, that would not be changed. The Yellow area are field information that will be changed depending on which content type is selected. Currently we only support Joomla Content - content type. The change we are requesting is not to add new content types - it is to allow the edit content area (yellow color) to change fields depending on the content type. How are the field information changed - by selecting the content type - an AJAX call would be called to pull the content input field details from the content type file. That would include the fields that requires to be entered for a specific content type. We would like to keep a clean look - so we will not accept the design to include a "pane" - we would like to keep it as shown and the yellow area on the image would change automatically when the content type is selected.