I went through the 'harry potter' interest tag on Dreamwidth, and found more promo-welcoming communities.

hpslash - slash and femmeslash
puppylove - Remus/Sirius

I also dropped comments on mod journals at some HP communities which as people to contact the mods before doing promo, so I'll let you know if I hear any 'yes, go ahead and promo' responses. :)