Yes, this will all work well together.
You could actually use the 10A regulator, instead of the 20A one. However, go for the 20A, for a few more pounds, as you might add another solar panel in the future, and it might be more efficient.
If you are going to have someone fit this for you, just check they are happy with it all.
Also get a split charge relay fitted, so that the engine charges the leisure battery. This is actually cheap and a better way or charging the leisure battery. You’ll arrive at destinations with a charged battery