Hi,
Displaying the stock for each option is possible with a small customization.
You'll have to edit the file product / option.php via the menu Display>Views.
There, the "yes" choice is displayed with the code:
$option_values[] = JHTML::_('select.option', $optionElement->product_id, $text);
so to add the stock to it, you would have to change it to:
$option_values[] = JHTML::_('select.option', $optionElement->product_id, $text. ' '.$optionElement->product_quantity);
To add a waitlist link, you would have to add the code:
<a class="hikabtn" rel="nofollow" href="<?php echo hikashop_completeLink('product&task=waitlist&cid='.$optionElement->product_id); ?>"><span><?php echo JText::_('ADD_ME_WAITLIST'); ?></span></a>
However, it's a bit more tricky as you need to still display the name of the option, and display that waitlist button only when the option doesn't have stock. So it needs rearranging the code of the view. It requires a developer to work a bit on it to rearrange the code.