Hi,
There are several solutions based on your needs and skills:
- You could enter the full description in the description of the product, and create a custom field of the table "product" via the menu Display>Custom fields so that you could enter a short description and display it on the right side (this requires the Essential or the Business editions).
- You could add a read more tag in your product description and use the product page layout "tabular" (option in the HikaShop configuration). This would allow you to have a the text before the read more tag on the right of the image and the full text at the bottom.
- You could also do some customization of the file "show_default" via the menu Display>Views, along with a mix of the solutions above to display the elements exactly how you want them to be.