Yes it is possible to stream straight from a smartTV. You just need to look for a seedbox with Plex feature available.
And of course, your tv needs to have the Plex app available to be installed.
This has become essential to me, even though I have pretty much a ratio that I’ll never be able to mess-up on most of my trackers, I don’t see me giving up of this anytime soon.
As for seedbox recommendations, there are several good ones that offer Plex support.
Seedboxes.cc is great on speed, support and features. Ultraseedbox and feralhosting are options a little bit cheaper (but not all plans offer Plex, so you need to pay attention on which one you’re choosing).