@snadge:
"Stretch" already explained by Westie.
"Noobs" is a packaged Raspbian version aimed at RPi beginners, contains a lot of program options that you won't need or use in DSLStats service, you can certainly use this if you wish opting to load Raspbian at startup.
"Stretch" is available for free download here:
https://www.raspberrypi.org/downloads/raspbian/As a Windows user I prefer to use the desktop GUI program option, works very well with DSLStats, have run this on RPi 1B, 3B, 3B+ and ZW's without any issues accepting the CPU limitations of the older RPi and the ZW's especially when data & webserver uploading is utilised.
I use a 16 Gb. memory card flashed in a Win. environment with either
Win32DiskImager or
balenaEtcher utilities, very easy process using the downloaded, extracted file image.
When you finalise your RPi/DSLStats setup, I would advise that you make an image of your memory card as they do have a finite life span, (relative to the quality of card you buy) I have had a few failures, it's then much easier to re-flash a replacement and get going again.
Regarding USB port current supply capability:
I have always thought that 500 ma. was the advised supply limit, certainly with USB-2 standard, has this increased to 900 ma. with USB-3 ?