Have you considered https://givin.gifts? They see themselves as the unofficial successor of redditgifts (they even let you import redditgifts gallery posts back when they were still online). They opened their Happy Holidays 2026 signups a couple of days ago and any premium user could also create a custom fediverse Secret Santa exchange.

I took part in every givin.gifts Happy Holidays exchange since redditgifts shut down and I'm happy with it. If there are any problems with your gifter, their team is really invested in smoothing things out and getting you a rematch if needed.