Zen Cart uses the 'medium image' size on the product info page. The size of the 'medium image' can be set in admin>>configuration>>images to whatever you want it to be (assuming that your uploaded images are big enough).
Look at tpl_modules_main_product_image.php (includes/templates/yourtemplate/templates) It is fairly straight forward how to disable the pop-up and leave only the image.
You are looking at:
Code:
<div id="productMainImage" class="centeredContent back">
<script language="javascript" type="text/javascript"><!--
document.write('<?php echo '<a href="javascript:popupWindow(\\\'' . zen_href_link(FILENAME_POPUP_IMAGE, 'pID=' . $_GET['products_id']) . '\\\')">' . zen_image($products_image_medium, addslashes($products_name), MEDIUM_IMAGE_WIDTH, MEDIUM_IMAGE_HEIGHT) . '<br /><span class="imgLink">' . TEXT_CLICK_TO_ENLARGE . '</span></a>'; ?>');
//--></script>
<noscript>
<?php
echo '<a href="' . zen_href_link(FILENAME_POPUP_IMAGE, 'pID=' . $_GET['products_id']) . '" target="_blank">' . zen_image($products_image_medium, $products_name, MEDIUM_IMAGE_WIDTH, MEDIUM_IMAGE_HEIGHT) . '<br /><span class="imgLink">' . TEXT_CLICK_TO_ENLARGE . '</span></a>';
?>
</noscript>
</div>
Change it to something like:
Code:
<div id="productMainImage" class="centeredContent back">
<?php
echo zen_image($products_image_medium, $products_name, MEDIUM_IMAGE_WIDTH, MEDIUM_IMAGE_HEIGHT);
?>
</div>
Putting the image where you want will involve changing the line:
Code:
<div id="productMainImage" class="centeredContent back">
to
Code:
<div id="productMainImage" class="centeredContent forward">
There is a quite a bit more programming involved in getting the additional image thumbnails to behave the way you want but perhaps someone has done it before.....
Fingers crossed.