A couple months ago, I visited a farmer's market and walked up to a table where several breads were on display and made a great discovery. A company called 'Bread Basket Bakery' makes wonderful vegan breads and they ship FedEx as well if you are not able to visit their store locally.
The version I bought which is not on their website is labeled "Unsweetened" and it has 0 g of sugar and only 90mg of salt. Other varieties of vegan bread include nine grain, raisin wheat, sunflower, and Swedish rye.
So if you are having trouble finding a good vegan bread, I recommend checking out their site.