I suggest you go with a Lizard Folk. They get a +1 LA 2d8 HD, which gives you 2 levels to expand on. Grab 2 levels of Barbarian. D12 HD, +2 str and con boost, Swim underwater, YAY! for swamps!!
. They also get I believe a +6 Natural armor. Best armor a barbarian can have without the use of heavy armor is Mithril Full plate.
+6 NA, +9 AC, +5 Dex armor bonus (IF! I remember correctly. Yeah for a 5th level character thats pretty damn good if you ask me.
Thats a +20 AC all together, if I remember correctly, but dont hold me to it as I am going off my memory which hasnt been all to good lately. +10 Base. OR! if you wish, grab 2 levels of fighter instead of barbarian, grab a shield and that will boost your AC over 30+ without magic items, you got the AC, you look nasty as well.
OR!........Warforged Fighter 5, Warforged Juggernaught 5/XXX10, if you are allowed eberron races and such.