I like the idea of ghost. Stall teams already pack Blissey as a normal type, but she can't really lay down other layers, so there's no need for worry that she'll setup moreso after you fail to spin what's already there.
On the other hand, poison has an added advantage of being able to absorb toxic spikes, and still gets walled by common Skarmory/Forretress. The ability to absorb spikes is likely what makes Tentacruel one of the best current spinners, since it won't get Toxic'd while coming in.
...Perhaps a Ghost spinner, for Blissey to wall it, with Steel secondary. This way, Blissey can wall it, it's immune to Toxic Spikes, it's resistant to Stealth Rocks, yet still very fragile. It would be countered by both Dugtrio and Magnezone, being trapped by both.
Of course, Poison or Psychic can also be used in place of ghost, but I don't think any Dark Pokemon are being used for anything outside of Weaville.
In short, I'm rambling due to being tired. Ghost and Poison are best options for typing, due to not screwing stall teams too much, and the actual typing of the Pokemon doesn't matter, since it's not like there are any "Normal Type" rapid spinners anyway.