Re: Is this a Realistic plan?
Personally, I think your management would be the same for the nuc and the package. The nuc just has a head start on the package. So now you have two colonies, you plan to run them with a deep and a medium as a brood nest.
As soon as the frames in the deep are 80% drawn out (8 of the 10 frames), put the medium on the hive. I would also be feeding 1:1 sugar syrup, as long as they'll take it. It helps them build up quicker, and build comb faster. They may not NEED it, as you probably have a flow on, but if they take it, they'll use it and it will build them up faster.
As soon as the top medium is 7-8 frames drawn out and filling/full of brood and honey, I'd add another. As long as they're drawing and filling, keep adding supers. You want them as strong as possible by fall. Once they get the deep and first medium done, you can remove any feed. If they quit taking feed, remove the feeder.
Oh, and in GA, you better have small hive beetle traps in your hives. I've had real good luck with anywhere from 2-6 of those "beetle jails" isntalled between frames in the brood area... 2 traps in each box. Put mineral oil in them.
Now, is there any particular reason you want a deep and a medium for your brood nest? Many folks run two deeps, that makes it easier to exchange frames, or reverse boxes, or make up nucs and splits as you expand. Doesn't matter to me, but think your future plans through.
Winter stores - you need to realize winter stores are different from brood area. for instance, I run my hives in two deeps for the brood nest. Depending on how they constrict the brood nest in the fall and back fill with honey, and depending on how heavy the colony is, I'll either leave the two deeps with nothing else, or add a shallow super for additional winter stores. In GA you may not need to be concerned about a large amount of winter stores, but you might need to be aware of when the dearth is on forage. Your bees still might be able to starve, late fall, or late winter/early spring.
Queen excluders, some folks use them, some don't. If you do, I'd suggest installing it AFTER the bees start drawing comb in your surplus super. That makes it easier for them to get started, but put it in before the queen gets up there. And yes, you must remove it in August or thereabouts, so the queen can move up with the cluster into stores as winter progresses. You don't want the queen trapped below the excluder unable to get to food...that would also keep the cluster with her, and they'd starve.
Hope this helps.
"If all you have is a hammer, the whole world is a nail." - A.H. Maslow