Question on yeast quality?
Yes, quick yeast and instant yeast are the same thing.  It doesn't have to be proofed in warm water before being mixed into the dough.

SAF instant yeast is a good product, so personally, I wouldn't spend so much more for a specialty brand.  Both brands contain yeast and an emulsifier, and SAF also contains ascorbic acid (which acts as a dough conditioner).

Resources:


SAF Instant
Doves Farm
Ascorbic Acid