ol' Blue,
It's been too may years since I've fished the 'hooch in April to give you an accurate opinion on what flies work best that time of year. Hopefully some of the FAOL locals will chime in. I did a Google on the 'hooch and found a couple of sites worth checking out. The 'hooch is a wide river so I would use a 6 wt to give me some extra casting distance, especially if you are not floating the river. Sorry I can't be of more help.
http://www.riverthroughatlanta.com/
http://www.springcreekanglers.com/abouthooch.htm