Don't go with 4k with this one! First of all, only season 1 is available in 4k and second of all, the source for the transfer was just 2k. Also the 4k blu ray format sucks because of it's density. A tiny scratch destroys a huge amount of data, often more than error correction algorithms can compensate for.
I have to disagree. Blu-ray/4k (same tech in both) do not suffer in the same way from scratches as Dvds. As someone who has watched maybe a 1000 blu-rays and a 100 4k disks, I can't remember the last time I had issues with a disk playing. Dvds it was maybe 1 in 6 that were problematic.
I have seen season one in both blu-ray and 4k and the 4k is exceptional. If you have high end audio visual equipment then wait and get the 4k set once it all gets released. Otherwise go with the blu-rays as it still looking great.