The only issue is there are not a whole lot of suspension forks made to fit this bike. There are two key items, it has a tapered head tube and a thru-axle, you could swap then wheel out for a standard quick release style like the X, but it's not advisable. There are mountain bike forks made for 29ers, which will work, but they will affect the geometry of the bike because most of them are much longer than the ones made for this type of bike. X-Fusion makes a fork that you could adjust to 80mm of travel and that could work. It should only have a minimal impact on the geometry.
The fork used on the Turbo X is a new fork from Rockshox called the Paragon and it's really made for a 700c wheel with a quick release, something that hasn't been done much previously in the suspension market. There are some cheap ones out there made for hybrid bikes, but not to many real good quality ones with thru-axles and such. The thing is, manufactures generally want to make something for a large market and the one large potential market for these forks is Cyclocross, but they don't use them. They could make them for hybrid bikes, but they generally don't warrant the higher price tag of a quality fork.
Sorry for making my response so long, I'm just trying to express my understanding on this. I hope it helps.
You might want to just get the Turbo S and put a Bodyfloat seat post on it. I did this with the Super Race I've been riding personally and it has made the world of difference. My bike is just as rigid. You could also consider putting a set of balloon tires on the bike allowing you to run them a lower pressure and creating some shock absorption.
I think if I was in your shoes I would get the S, but maybe some current owners can chime in.