Touratech offers several levels of shock. You'll want hydraulic preload. I went up a couple of steps from the basic, but it gets stupid expensive after that. I did spend a bit over $3k. Ohlins 30mm kit on the forks and TT Explore on the back. I was going to just get the TT HP version, wanting the better, more robust and longer travel pre-load adjuster, but after talking to a few shops decided to take the plunge and up that to the Explore shock with hi/low speed adjustment so it would be more able to dial in to my needs. I run heavily loaded, sometimes pushing two up weight with only me, but other times stripped down and light, so wanted as much range as I could get. It's better than my tired stock set up was with 60k plus on the shock and a much stiffer spring than oem for nearly all of those miles. I'd already replaced the first shock at 50k with another low mile stocker that a forum member very generously gave me before my '13 IBR ride.
I think, (being a suspension noob), that the Extreme might be overkill for anyone just doing touring. At the end of the day, it's only ~$300 more for the Extreme than the Explore though, so you are certainly stepping up the costs.
I'm happy with the compliance of the Ohlins front and TT rear set up I have, but honestly need help getting it better dialed in. Or time to spend actually reading the manual that came with this stuff and following the instructions!