ok i figured mine out so i'm happy.
just in case anyone else wants this weird thing, here's what i did:
installed cross sell and have it at the bottom of my product pages (only i did this 3 times because i want 3 different cross sells - long story)
i wanted the links to show up in the shopping cart based on the model (which i don't use as model #, but as a text field that i use to sort for other things like shipping regulations certain products have, etc), so to the shopping cart header, (in includes->modules->pages->shopping cart), i found the product array list at the bottom and added:
'model'=>$products[$i]['model'],
right above:
'attributes'=>$attrArray);
Then in the shopping cart template, I added if model = x, then show my link stuff. i did this under attributes, and i did a span class so i can mess with the css to set it apart from the attributes. heres an example:
<?php
if ($product['model'] =="Pneumatic Pump" OR $product['model'] =="Spring-Piston") {
?>
<a href="<?php echo $product['linkProductsName']; ?>#crossSell"><span class="ammoWarning">DON'T FORGET YOUR AMMO!</a></span>
i like it because i can make the link different from the cross sell heading text (which in this case is "Ammo for this gun" or something). the link takes them back to the specific cross sell on the product page (#crossSell2 in some cases) so they can see their choices displayed all beauteous in the columns without crowding up the shopping cart, BUT i have the cross sell stuff under the Add to Cart and navigation stuff so I don't think it would make people forget to add the main item and have to go back to find it after looking at the cross sell items.
Seems to work, but I'm sure it was too easy.