OpenCart Mobile Optimisation and Multi-Buy option added to website

I require assistance to ensure my OpenCart site is mobile optimised. The theme I am using states it is but when checking on my phone this is not the case.

Secondly, I need to add a multi-buy option to my site - similar to the link below:
http://www.ebay.co.uk/itm/2-x-USN-Pure-Protein-GF-1-2-2kg-5lb-Shaker-All-Flavours-IGF-1-/321201518081?pt=UK_Health_Beauty_Vitamins_Supplements&var=&hash=item4ac91a3601

Let me know when you can start and any examples of when you have completed work similar to this in the past.

Thanks.