You've come to the right spot.
So if we are talking about what Bama was doing in '13 then it's not very similar to what they are doing modern day. They used to run very basic cover 2/quarters/man scheme and just out athlete the offense. With Pruitt they've gotten far more aggressive in their blitz packages and play more Cover 3.
Uga this past season ran a lot of base 34 defense. Like they did at Bama they play a lot of base quarters coverage with some cover 2 and cover 3 mixed in. What they did differently this year is they did bring a lot of different blitz looks on passing downs. IMO they were one of the more successful teams in blitzing on passing downs that I saw.
Outside of their base 34 defense, they mostly used a 3-3-5 Nickel as they passing down defense using 3 bigger bodied DL and their best pass rushing linebacker. Those are about the only two personnel packages they used.
For the defensive line, you're going to need two bigger bodied, run focused players and 1 slightly smaller penetrating defensive linemen. It's a lot like what the Falcons/Seahawks are doing with their fronts. Two 2-gapping players, likely playing DT and LE on the game. Both should way north of 310 pounds. The RE should way in the 285-305 pound range and be a little more athletic.
Your outside linebackers for the most part are going to be interchangeable. Looking in the 6'3+ range and north of 245 pounds. One will blitz more than the other, that's usually the ROLB, so if one guy can cover a little bit he's better off at LOLB where he will lineup over the TE more.
Your middle linebackers will be thumpers. If they are athletic too then even better, but first and foremost you are looking for players who can defend the run. Looking for 6'2+ and north of 230 pounds.
Corners we are also going big. Looking mostly at guys taller than 6 feet, the taller the better. Looking for athleticism more than pollish.
Safety is actually the position where you can get away with a slightly smaller player. They will be pass first defenders who don't have as much of a dedication to the run since the rest of your team should be able to lock that down. Looking in the 5'11+ and north of 190 pounds, guys who can really fly around the field.