A: Treat it as episodes 23 and 24 of Season 4. Name them Prison.Break.S04E23.The.Final.Break.Part1.mkv and S04E24.Part2.mkv .
Buy the complete series on Blu-ray (best quality) or buy the digital bundle on Vudu/Apple TV.
Use consistent naming so any media player (VLC, Plex, Kodi) can autodetect episodes. This article cannot ignore the elephant in the room. When you search for "download prison break complete series portable," many top results point to BitTorrent, pirate streaming sites, or Usenet groups.