I live in Tennessee and have similar temps to what you see in Alabama. Here's my take:

1) Think layers rather than one warm jacket.
2) A long-sleeved compression shirt as a base-layer will add warmth to anything. UnderArmor and the like are warmer than the thinner, cheaper ones. But even the thin ones are a lot warmer than you might think.
3) A compression/base-layer plus a thin fleece plus a wind-breaker shell is all you'll ever need.

If you're on a budget, go to Target and look at the Champion C9 stuff. Their compression shirts are $17. They have great, dense, but thin and light fleeces for $20-$25.

Cycling-specific stuff is nice because the sleeves are a bit longer, the back comes a bit lower, and it all fits tighter so it doesn't flap in the wind, nor does it puff out like a parachute if you unzip the top a few inches if you get too warm.

I mix cycle-specific stuff (for the fit, as mentioned above) with the C9 stuff and it works great. I have a Pearl Izumi thermal jersey that fits snugly and works down to about 45F with just a base-layer. Below that, I add a Performance Bike shell ($40) that is just a nylon wind-breaker, but again, cut for cycling, and I'm good to go as cold as I want here in TN.

They layers approach also makes it easy to fine-tune your clothing to match the day's weather, and allows more options to strip some off if you get too warm.