From your post if you just want to permaseed either one from the recs is probably fine.

I’ve used rapidseedbox and ultra.cc in the past, (one months each) and that’s just because my server at home is down in the meantime.

Idk how much automation you need and what can they provide though since I just manually load them when I use it.

My recollection of rapid is nice, they have pre-installed tools like SFTP and your choice of torrent client.