I'm in the process of building an on-line sales site, and I'm using the free PrestaShop software. I was pleased to see that it includes a number of Bitcoin specific modules - Two that take payments via the blockchain, and another that uses coinbase. There are also some wallet options, and I haven't yet looked to see if those are suitable for Bitcoin.
The promotion of Bitcoin via the increasing numbers of such sales sites will surely contribute to the growth in Bitcoin use right where it is needed - international sales,and low cost sales by small retailers.
I'd recommend using GoCoin & Bitpay.
Both have Prestashop Modules and both are amazing.
Just a tip.