Depending on where you live you'll need either a SN Subscription (outside habs region) or an SN and TSN Subscription (inside the region). I live in Toronto and I have SN and it's fine a bit glitchy at times but I get all the games in english or french. if you lived in MTL though the games that are covered by TSN are out of bounds and you'll need both. Subscription to SN premium is $200 for the year, TSN is like an extra $20/mth on top of that. It's been worth it for me.
Now in terms the device, the fire stick is just a player, no different then an apple TV/ Roku/ chromecast. If you have a firetv/smarttv or an existing smart tv device you may already have this available. The only watchout is that an apple tv seems to hate the SN app so i actually have a fire Stick in my lviing room and an apple tv in my bedroom. When watching in my bedroom on the appleTV it seems to hate SN and It's smoother to stream via my phone/ Ipad when watching it natively on the AppleTV. I work for the smile so i'd obviously recommend a fire stick, there is different quality so get the one that fits your TV. I.e. don't buy the 4k if you don't have a 4k tv. Otherwise your good to go