Here are a few common points that I have found:
I have heard good things about both Coinbase and Bitpay for merchants. However, Coinbase waives the 1% btc->usd direct conversion fee for the first 1mil of sales. https://coinbase.com/docs/merchant_tools/pricing
I think it is also important to address the fact that this is still a very new territory for merchants and there are bound to be some issues along the way (technical and political). A willingness to work through the growing pains is definitely important.
I am very excited that there are others soliciting business to start accepting Bitcoin and I wish you the best of luck.