My dear departed mother was never much of a drinker but every Christmas morning the two of us would have some form of champagne cocktail. Often a Mimosa, which went down a treat. BUT the year we tried a champagne and strawberry liqueur mix was a disaster. Well not for mum and I, we giggled through until mid afternoon when crashed for a nap. When we woke we realised the peas went unserved, some people had the wrong presents and there was something very charred in the oven. The family still talks about the year we were too tipsy to cook lunch. This year it'll be straight champagne (and after 8 years I still miss her dreadfully).

Both have their place depending on taste and budget.

A lot of the time they build a core filled concrete block wall then construct another stone wall against it. The concrete block wall takes the job of retaining while the stone is for looks only. It does depend on what purpose the wall is performing. For example a retaining wall higher than 600mm (usually) needs engineering by a structural engineer which is easier to achieve with core filled concrete block on footings rather than just solid stone. You never mentioned the purpose of the wall which is a vital detail as there can be numerous ways to achieve similar outcomes.

Personally I'd be very careful adding stacked stone next to the dark bricks. I think stacked stone can work next to rendered areas to provide contrast/add another element but next to dark bricks it could easily look too busy/too much. It's your home though so do what will make you happy when you drive up to it! If you're dead set on the stacked stone then find the brick manufacturers location and ask to speak to one of their designers for an opinion/options. If they can't help then ask brick manufacturer for the addresses of some properties in your city that have used your particular brick and check a few out. They will usually give you some addresses if you explain what you're trying to do. I'm sorry to have not answered your question as to what colour stacked stone to use. Good luck, exciting times for you.