<?php
$_category_detail=Mage::registry('current_category'); //Get the current category
$product = Mage::registry('current_product'); // Get the current product
$productId = $this->getProduct()->getId(); // Get the current product ID
$category = Mage::getModel('catalog/layer')->getCurrentCategory(); //Get the current category id
?>
<!-- standard pants - sizing chart -->
<?php if(in_array($this->getProduct()->getId(), array(372,363,354,349,344))): ?>
<div id="sizingmap">
<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('sizespecpantsstd')->toHtml(); ?>
</div>
<?php endif;?>
<!-- slim pants - sizing chart -->
<?php if(in_array($this->getProduct()->getId(), array(339,334,329,324,319,314))): ?>
<div id="sizingmap">
<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('sizespecpantsslim')->toHtml(); ?>
</div>
<?php endif;?>
<!-- jackets - sizing chart -->
<?php if($category->getId()==10): ?>
<div id="sizingmap">
<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('sizespecjacket')->toHtml(); ?>
</div>
<?php endif;?>
thank you guys for your input, I was able to produce the result by putting bits and pieces of everyones codes together.
Cheers :)