Can you use regular store bought yoghurt? If so; which kind?

By all means you can. Greek yogurt is significantly thicker than conventional yogurt. Fage has more of a buttery flavor, while Greek Gods is more tart, plain in both cases. The recipe appears to prefer the tart end of the flavor spectrum, so I'd suggest using Greek Gods.

Hi Rebecca,

Yes you definitely can! I recommend and thicker Greek style of yogurt like Fage or Chobani. Please let me know if you have any additional questions.

Best,
Erin