That would be a really interesting thing to be able to pay with any ERC20 tokens but you need to build a system to match the payments on another exchange with liquidity. Maybe try adding new accepted ERC-20 tokens slowly and only the ones which have a large community who use the tokens for various payments. You're trying to do a big project so I guess you will need a couple of skilled blockchain programmers. 
You also need deep markets and liquidity. The biggest issue with using tokens or crypto for goods is the supply chains are still in fiat. So at some point in the process the coin will have to be exchanged. That kind of adoption is going to take a long time and will most likely be filled a niche currency in the markets that need them. (like the Marijuana coins)