I need to use GData to access to google calendar, but my server need to pass by a proxy to acces to the web. A friend work a litle patch to add http proxy support but we need https proxy support for google auth.I think at this moment the best possibility for me it's to modifiy Zend::HTTP to use CURL to replace fsocket.
have you tried Zend_Gdata? http://framework.zend.com/download/gdata
it has Zend_Http_Client::setProxy -ers
