I actually like both of the suits you posted, you have a tough choice to make! If you don't already own a grey pinstripe suit then perhaps go for the Reiss as grey pinstripe suits are a classic and are suitable for so many events.
If you already own a few then perhaps branch out and get the brown Holland Esquire suit. I think it would be striking in person as I've seen men wearing slim fit brown suits at the races and they looked really stylish and stood out. You can also have fun accessorizing a brown suit with vintage accesories.
Either way you can't go wrong as both of the suits you posted are great choices.