Magento：自定义产品搜索结果（有自己的表格）

I'm trying to generate a search result page with a custom product collection. The plan is to create the product collection based on attributes the customer can choose in a custom html form. I have an IndexController

public function indexAction() {
    $this->loadLayout();
    $this->renderLayout();
}

public function postAction() {
    $postData = $this->getRequest()->getPost();
    $productCollection = Mage::getModel('mymodule/api')->checkPost($postData);
    //$this->_redirect(???);
}

which is receiving postData from my form.phtml and passing it to my checkPost function (postData gets evaluated) which returns a custom productCollection. I would like to redirect the customer from the form to a category/search result page with the productCollection as results but I have no idea how to get this done.