There's a number of ways you can achieve full deletes. It's going to partially depend on what you want to spend and how good of products you want.
Yes you will need a tuner. H&S MiniMaxx or XRT pro, RaceME, Smarty, and Torque Tech all offer delete capable tuning. At this time H&S is the only one of those that offers custom tuning and good transmission tuning. The tuner is the biggest decision as it will be the most expensive part of the delete puzzle and there's a large price difference between the options.
As fars as an EGR delete goes the tuner will disable the EGR however I recommend removing it from the truck completely otherwise exhaust gases will get into the intake. Plus the coolers are known to crack and leak. Getting rid of everything also cleans up the engine bay a lot. Sinister Diesel makes the best EGR/cooler delete for about $195.
For a turbo back exhaust I recommend Flo Pro. They make a ton of different configurations in both 4" or 5". Unless you plan on running 650+ horsepower down the road the size you choose doesn't matter as a 4" will support that much power. You can fully base your opinion on what you think sounds better.
I'm running an H&S MiniMaxx with the MCC and Overdrive unlock allowing me to run full custom tunes for both the engine and transmission on it. Right now I'm running tunes from Ray at Double R Diesel and highly recommend him. His 5.9cr sound is about the best sound you'll get from a 6.7 without going to a full second gen swap. Then I'm also running a Sinister EGR delete kit and 4" Flo Pro turbo back straight pipe exhaust. Here's a video of my truck running that setup.