If you're after low profile specifically, then you should look for the Quadro cards for that same generation, (Pascal), like the P400, P600, P1000 etc. The P1000 is probably your best bet as it also has 4GB of VRAM.

I see one here: https://www.trademe.co.nz/a/marketplace/computers/components/video-cards/pci-express/listing/5174372645

I have one of those in my Plex server and it handles transcoding multiple streams easily, (just not AV1)

I've been reading only good things about the Intel arc a310 which supports av1 if you want a bit of future proofing ,  if you can find one

I use a Quadro and it works a treat.  I don't think it'll do AV1 transcoding but I'm not using that very often yet.  I got this one for around $100 and you can find them all over the place.