Browsed through images at moe.imouto for high res pictures. What I did was crop and re-size the image to a 1:3 ratio then blew it up to 50x150cm and checked it out actual size to see if it looked good enough.
This is the result after picking it up at the post office.
Kagamin sitting comfortably on top those nice oppai.
Unfortunately Kagamin figma does not come with the dakimakura.
I ordered dakimakura from this ebay seller and saw they had a custom option. I tried it out and I do plan making another if I find something I really want.
OH and about not showing the bottom half well... the goodies are down there ^.^