I agree with Marc.

Also the 160vc is beautiful but it takes more light, ample light is a rarity at a wedding unless you bring it with you. The flexibility and quality of the 400 is probably a better choice.

I'd also suggest that with regard to the fast B&W that you stick with the Neopan you know. If you experiment with a "new" film at the wedding, you may be experimenting with a "new" relationship with your brother.

I'm not saying you can't/shouldn't try this, I'd just be darn sure you have the important stuff in-the-bag first.