The best match for him? What do you mean?
The people want it, Manny Pacquaio wants it, what other reason? Do you think Manny will still find other fighters other than Floyd? They are in the age of retiring and you still want him to find other players that the people don't want Manny to fight with?
You think Manny Pacquiao would win the fight against (undefeated) Floyd Mayweather?
Mayweather is a monster so I don't think it would be the best match for Manny to close his career... if he doesn't want to end it with a loss, at least.
Oh yeah. He fought Keith Thurman, who's "undefeated" by the way before they fight. Undefeated or not what is that? It is meant to be broken, that is why Manny wants to fight him.
I know you are a supporter of Mayweather and I respect that, with a loss or not people will still remember Manny Pacquiao as a great boxer. Floyd is a great boxer too, one of the greatest as they said it, but Pacquiao is different. He has a story, a rag to riches story and he doesn't just fight because he wants to, he also fights for his people and for his country.