I know there are no online stores that can accept payments in the form of bitcoin. But I've heard Amazon and Alibaba plan to accept payments with bitcoin. But not sure about the news truth.
There are actually online stores that allow the payment in bitcoin. I have used purse before to purchase some few stuffs using bitcoin which went smoothly.
The platform itself has integrated bitcoin wallet and that can allow you to buy anything in bitcoin based on the equivalent price in USD at the particular point in time that you are buying it. I am pretty sure there are so many other platforms like this and only if you can do some little diggings you will find them.