Northern Brewer is my go to most of the time, good ingredients, flat rate shipping... I am pleased with my one order from Midwest and their customer support as well - Both times I sent them an email I got a response in less than 10 minutes.
Several web stores sell Brewferm kits. With the right yeast (WL500 or Danstar Belle Saison, for instance) and some TLC, they make tasty Belgian-style brews.