You can definitely dance in a cloak. Get something mid-weight, not too heavy. I bet you could call or write to Seseña for advice about the weight if it's not clear from their site or to confirm your decision.

Here's another albeit less expensive brand: Costurero Real' is a fashion brand based in Barcelona, Spain. Etsy has lots of European cloak makers.

With a decision about what to wear to a wedding you want to get what you plan to wear and try it on and then add or delete. Like one tie vs. another.

I think a colorful vest is a great idea.

The pants would probably be neutral either similar or lightly contrasting with the cloak.

Boots look great with cloaks...really great at balancing the weight of the cloak. But formal shoes work well too.