Hello i have experience in IPTV service, i mount services with Astra Cesto, with stalkers server, with flussonic, and with Xtream code.
for me the best is Xtream Code, becase this integrate transcode, control users, control stream, and you can manage account with many device, android, mag's, control acces online, m3u list, etc etc etc, this can integrate with whcms panel where you can control the payments by your customers.
i have time to integrated to your team and build the solutions, actually i manage 2000 users in my server all with Xtream code panel, i can give you acces example for this panel and you can show with this use