There are a couple of ways to skin this cat. First you would need to add the radio boxes to the form and label them properly;
<input type="radio" name="radioURL" value="http://cgcc.sage.eou.edu/opac/en-US/skin/default/xml/rresult.xml" />
Then you would use jQuery to determine the value of the selected radio box;
var checkedURL = $('input[name="radioURL"]:checked').val();
checkedURL should contain the URL associated with the one that is checked. Then you can use that URL in an AJAX function to submit the form to the appropriate location.