Other than Spring rains, you should be fine weather wise. The Google bicycle route looks pretty good, avoiding all major cities except Memphis. You might check out how cyclists manager the river crossing there. Maybe somebody on here will have some first hand knowledge. You can also go over to www.crazyguyonabike.com and do a key word search.

Being prepared to camp is a good idea just in case a motel doesn't always pop up when you need one. 50 miles a day is about average for most touring cyclists. Allow yourselves at least one day off a week, and enough spare time to sit out days of prolonged, heavy rain.

Make sure you are highly visable to motorist. Bright jerseys, and slow moving vehicle signs on the rear of your bicycles. Be doing yourselves and motorist a big favor.