I wouldn’t try to build a store with 100,000 products on Woocommerce without first looking into a couple of things. It might be possible, but I think that the platform may not be up to the task of what is required for a store of that size.
Woocommerce is fine for smaller stores when you are first starting out, and it might work out for a larger store, including the size you are planning, however, I would contact support at Woothemes before attempting, to see if there are any practical limitations or special requirements.
Also, from my experience, there are certain limitations with any shared hosting that is likely to be exceeded with a store of that size. Don’t be fooled by claims of unlimited bandwidth, or unlimited storage space. Hosting companies often offer packages with no defined limitations on those features, however, they always have limitations on CPU resources and memory allocation. A store of the size you are planning will definitely hit those limitations on shared hosting unless you are on a very high-end package.
I recommend that you contact support at your host and tell them the platform and the size of your planned store. They will let you know if your package can handle it or not. In many cases, they will tell you to not even dare try that on their shared hosting servers.