first attempt at croissants

Greetings folks!

I've read quite a few threads before starting out and have settled on this one as a good introduction to the technique...I found the link here from a forum member's (bakingfanatic) blogpost here: https://bakingfanatic.wordpress.com/2013/08/10/croissants-pains-au-chocolat-2/ 

My questions relating to this recipe is the exact best flour to use (calls for either strong plain flour or a blend of strong plain and plain and I'm not sure what this really means)...I've looked through some threads and can't seem to narrow down the protein percent that works best? My impression is that the ideal flour may fall somewhere between my KAAP and pastry flour? I was thinking about combining the two? If so, I unfortunately have pastry flour from the bin at the health food store, what percent would I actually be shooting for if I mix them? (I'll stop in while out shopping to see if they list the protein content).

Am I over-thinking this?  :-)

Just don't want to add to the difficulty of having never done it so trying to line up the ingredients first. Off to the store for some super fine sugar (referred to as caster sugar in the recipe). 

OOPS, it also calls for easy blend dried yeast? I have both instant and dried active, will either of these do and will I need to adjust the amount?

A couple of last questions, is there a SD recipe that any would recommend for the same pastry (for a future attempt)?

Any other advice?

Thank you!