First off, there are plenty of names that you can immediately write off for one reason or another. To be perfectly honest, the Real Americans is just a tag team and it isn't a spot that can be useful to someone who is above it. Therefore, anyone who is established enough in their own right to not need a spot on the Real Americans team has no real purpose being the new member. Say goodbye to your names like John Cena, Batista, Randy Orton, Alberto Del Rio, Big Show, etc.
To a similar extent, the wrestlers who have gimmicks that are solid enough to stand on their own two feet—but just haven't reached main event status as of right now—are in virtually the same league. Why would you ever want to sacrifice Bad News Barrett by putting him on this team, or Bray Wyatt, or even The Miz?
But we can narrow it down even more than that. You also have to strip away the people that just wouldn't be a good fit. Does it make any sense whatsoever for someone like Justin Gabriel to be on this team? Wouldn't it be ludicrous for Yoshi Tatsu to be the new member? Can you really see JTG or Goldust or Evan Bourne fitting in?
When it's all said and done, you're left with only a few names that can make any sense, and I think there's really only three people that stand out as potential choices for this spot.
1. Curt Hawkins
To say he's been inactive is an understatement. Somehow, Hawkins still has a job in WWE, but he hasn't really been seen in years. You can probably count the amount of appearances he's had on television since Tyler Reks left on one hand. If you nix the Superstars and Main Event ones from that list and only focus on Raw and SmackDown, the number might actually be zero.
Hawkins is a blank slate. Nobody cares about anything that he's done because he did nothing of note, and even if he was an okay partner for Ryder when they were Edgeheads, that was so long ago that the statute of limitations has passed.
Here is your opportunity to bring Hawkins in as an average worker that will never go beyond the tag team division, so you aren't wasting someone who is better that can have a singles run by weighing them down in the tag team spot of the card.
2. Scott Dawson
Bringing up an NXT guy makes even more sense than using Hawkins in my mind. I don't think is old gimmick would end up shooting him to the top of WWE any time soon, so it might be better to just abandon it while you can and save yourself the effort and eventual disappointment. That's not to say that he should be released. Rather, it's worth a shot to see what he can do in an already established gimmick idea where he doesn't need to carry the weight of his own character.
The downside to him at the moment is that he is injured, but without knowing the timetable for his return and how long WWE is willing to wait for a new tag team partner for Jack Swagger, that could end up being a moot point.
3. Sawyer Fulton
Jack Swagger is deceivingly big and Fulton is quite a large fellow himself. If you want this tag team to appear like they are "salt of the earth" type people that are representative of old values, corn-fed country boys that work with their hands and all that rhetoric, Fulton can pull that look off. Vince loves his big guys, which is a bonus for Fulton.
To be perfectly honest, if given the ability to do what I would see fit, I would probably add both Fulton and one of the other two men to this team. WWE can use a few more 3-man stables to help counteract The Shield, The Wyatt Family, 3MB, Los Matadores and the proposed tag team of Miz + Dolph Ziggler + Zack Ryder that I honestly do hope happens, considering how I can't imagine any of those three making it to the main event any time soon, with WWE's limitations and track record.
Having the Real Americans consist of Jack Swagger, Sawyer Fulton and preferably Scott Dawson down the line could end up making a more than solid addition to the tag team division.