I am currently using both desktop and mobile version of the landing page. How am I able to target one specific device screensize (ipad) to show the mobile view rather than the desktop? I have come across mktoMobileShow but it would be great to have some advice.
Are your using a free-form Landing page template? This seems tt be the case, from what you describe, and they are not intended for responsive design. So the only views available are desktop and mobile. The switch form one view to another is managed by Marketo, and AFAIK, you cannot influence / change it.
You might want to consider using some guided LP templates, that can be designed for full responsive layout and therefore render well on all device types and sizes.