Not sure what kind of headroom you are refering too?
Switching to Ryzen will be a downgrade for gaming anyways.
Nomatter if you go with the 1600X or 1700, or whatever.
Most games dont really benefit from 8 cores atall.
Maybe a very few exceptions, but that depends on the gpu used and resolution aswell.
R7 cpu´s are mainlly interesting for content creators, and productivity stuff.
For gaming they dont really have that much to offer.
THe R5-1600X will perform very similar to a 1700 in the vast majority of the games.
They do perform fine dont get me wrong, but you dont need 8 cores 16 threads to play a game.
Thats why the 7700K is pretty much ontop of any gaming benchmark chart.
And as far as the future is concerned, there isnt really anything usefull to say about that.
Like i pointed out a couple of times.
Switching to Ryzen in your specific case only makes sense,
if you are doing some productivity stuff or content creation with cpu rendering and that sort.
Or if you plan to play with multiple VM´s in the future, if they ever get those iommu groupings fixed on am4.
Otherwise X299 will be more interesting for virtualization most likely.