I'll go for it.

「I’ll go for it.」は、「それにします(決めます)。」という意味です。

A: I’m looking for a good hair salon. Do you know one?
B: I heard the salon in front of Central station is the best.
A: Ok! I’ll go for it.

A: What kind of movie do you want to watch tonight?
B: I’ll go for an action movie.