It's all pretty simple IMO, and SHOULD be able to be accomplished without trading anyone. Everybody has varying opinions - particularly when it comes to whether or not we'll spend money, but with the young Pitchers making the strides they seem to be making there's little reason to think we can't absolutely splurge on either a right-handed bat to hit behind Freddie this winter. It's also pretty obvious who it should be.
I can - and have - made the argument that we COULD have signed bats in LF and at 3B this past winter, and still think it's still entirely feasible that we could do so again this winter to make a huge splash as the new park opens, but will just point out one for this thread. The ONLY salary of consequence that's on the books is Freeman's. You can unload Markakis at any time if you want his money off the books. If you can't get any prospects you're happy with right this moment, don't worry - if the Braves were to DFA him they'll have plenty of takers. Even if they were to release him, there's a better than 95% chance that someone takes his salary off their hands. So...
You go spend WHATEVER IT TAKES to get Cespedes to play LF and hit behind Freddie. If it's 5 years and $150 million, so be it. You move Inciarte to RF and you've got one of the best (if not the best) defensive OFs in baseball. You watch Ender, Mallex, and Albies closely the rest of the season and decide who you want leading off next season. For my money, it's Mallex. As others have mentioned, I'm much more interested in production - even at the expense of power. While he may not be the power so many people want, adding Swanson to this lineup is going to be a lot like adding a Lorenzo Cain. In essence, you're going to be moving everyone other than Mallex down at least three spots in the order, meaning you're not going to need NEARLY as much production from them.
CF- Mallex
SS- Swanson
1B- Freeman
LF- Cespedes
3B- Beckham/Garcia/d'Arnaud
C- Flowers
RF- Inciarte
SP
2B- Albies/Beckham/d'Arnaud
Keeping Julio allows you to trade from the prospects in the event you want to try to go get a C or a 3B - Jenkins or Gant and Sims for Lucroy, Profar, or Gallo would pique my interest. You keep the other one of those arms for AAA depth.
You're then free to draft BPA at #3. If Lewis slides, you can take him and dangle Inciarte in a year or so if he's on the fast track. If you want the faster moving college arm and Puk slides, you'll have him to replace Sims on the depth chart in short order. If our scouts like Moniak or Rutherford better than the other options, a Cespedes signing buys them time to develop at their own pace.
I know the idea of a big contract will get some people around here squirming, but overpaying for Cespedes is the easiest way to turn this whole thing around - in a hurry. Other than Freddie, no player in this organization stands to make $10+ million before 2019 unless the brass starts signing players to early extension. The Braves have never been in a better position to go get a big-time free-agent.