You could use any of them, but remember that Splenda is 1:1, ie one teaspoon is equivalent to one teaspoon of sugar.
Truvia (and probably Stevia) is a lot sweeter, and a third of a teaspoon is equivalent to one teaspoon of sugar.
Hi, I would check out Ewelina's posts and blog. Her baking recipes look lovely and she does mention which are the best sweeteners to use without any aftertaste and the best for diabetics. Post me your recipe too when you get a chance ewelina
I make muffins without sweeteners, i find the natural sweetness of the almond flour is enough or I add some vanilla seeds . For breakfast I would make savoury muffins and add herbs and spices for lots of flavour. The mini cheese loaves on Ewelinas site are yummy and I can recommend them for breakfast.