There are some good ones out there, just look for reviews. I haven't had any issues with transcoding with the provider I use on a $5/mo plan.

ultra.cc

Forgot to mention Bazarr for subtitles. Integrates seamlessly with Sonarr.

Sonarr with nzb360 to manage it. Completely hands-free, couldn't be easier to use once it's set up.

If you don't have your own hosting, search for "seedbox" hosting - there are plenty of great, relatively cheap options. I picked a hosting option which had the above apps already set up and ready to go, which made the whole thing seamless.