I buy Lidl 74% choc I think it has a nice taste, and cheap.
Almond flour is basically ground almonds. Coconut flour is lighter, so in cakes makes a lighter fluffier cake. I use either.
With sweetners it can be confusing. Some people find that some give them an after taste. I don't. I use canderel or splenda, but I think splenda is better when cooking. With measurements I would say try whats on the recipe and then next time you can always alter it if you find something too sweet or not sweet enough. Or taste it as you add it to see what you think.