I'm searching for a torrent client with following features:
Continuously download a file (so video files can be viewed while downloading)
Prioritize first and last piece of a file (without last piese some videos cannot be seeked)
Download files in selected order
Rehash only selected files in a torrent
Search in torrent/file names (I had >1k torrents)
Linux version preferable (I have a Linux NAS)
Clients I already tested:
µTorrent 2 - continuous downloading can be turned on with a hack, but no way to prioritize last piece. MKV files cannot be seeked with a hardware player then. Files can be only downloaded by order they are listed in the torrent file.
µTorrent 3 - IMO even continuous download haven't worked well. Still need a hack to turn continuuos downloading on.
qBittorrent - can continuously download a file and prioritize first and last piece, but you must select it for every torrent. No idea how to download files in selected order. I don't like the program itself though. Added: it just failed on downloading the last piece of a file although all peers I was downloading from were seeds.
Please note, first of all, that this practice is not encouraged, per Bittorrent etiquette. More here: link.
However, qBittorrent allows, once you started a torrent download, to right-click on it and request both sequential order download, as well as to download the first and last piece first. Hope I understood what your requirements are.
Deluge is free and open source, has a Windows version and has an option for prioritizing first and last pieces in its settings.
It can be configured to download only one torrent at a time, and then you can reorder the torrents to choose which one to download first.
It's cross platform (Python based) and it's a client-server app, so you install the daemon on your NAS and then configure the Windows app to act as a client; you can of course use the Windows client as a stand-alone app as well; there is also a web UI that you can install on your NAS to interact without any kind of client.