Swap vendor when customer selects customize!

Maybe you can help me.

I am looking for an option or app, to add to each product page. The option and upcharge would be to add an additional image to the shirt, such as a left chest logo design. Realizing that each design shirt and size has a specific sku number from the print on demand provider, I simply can not just add the information. what I would need to do is capture the order by changing the vendors name to deep sea dreams. then I would manually create the shirt using the print on demand provider to include the two designs and upload it to my printer.

so here it is in the short version

1 customer sees shirt but wants a left chest logo added to it
2 customer selects option to add logo
3 when this happens, the vendor info automatically switches to deep sea dreams
4 i get the order and using the print on demands app create the shirt with 2 images and then I manually order the shirt through the POD providers site.

What do you think?