Hi, so you want 5 languages. Let me just point out that according to magento requirements, in order to have the descriptions in every language I will need to create one product pack for every store view, with a different root category.
Now, it is important to analyze performance and how good magento will work having such a huge number of variables.
I would start looking at the possibility to configure sub domains for every language and try to go for a CDN in order to serve images.
The database manipulation will be sensitive, and building up a low render time is going to be essential.
As you can see, this is not an automated bid and I know what you need to make your project happen. You already have a lot of bids from Asia, which is ok, but my tight team and I know what it takes to build a store for real. Places like ernestalexander, fashionara, 80spurple are a clear proof of our success. We might not be the cheapest, but I can tell you we are as professional as you can get.
About design, its not a worry at all. I just need some pointers to build an exclusive advanced responsive template, just for you. We would start with some drafts, while we work on store and data integration. Remember magento 1.8 is out, so your store should also be as updated as possible.
Maybe we can discuss details whenever you feel appropriate, just let me know.
Thanks for reading.