Purolator Mail in my opinion. I used to ship from Vancouver to Saskatoon and they were always right around 24 hours. I received about a dozen orders that way, and they were reliable. Small box was about $35 (just a couple small bags).
You could get The Reef Shoppe or Bayside Corals to ship via Greyhound to Regina as well. Short distances Greyhound is pretty good, and both places have decent livestock pricing.
(and thanks for the comments)
