Can’t help you on provider as it’s all still shaking out following the recent issues. Once it’s settled down I will PM with details, don’t want to give bad advice. Some of the best providers are not accepting new subscribers until they have migrated their databases.
But IPTV works fine on virtually any platform. Kodi is the most popular, which you can install on fire stick with a bit of fiddling about, but loads of tutorials on YouTube, same on PC, just download and install. Or you can use something as simple as VLC media player as it’s really just accessing a M3u file on a remote server which then directs you to the right IP address for the stream.