Welcome JT. I also vote for the poplar. We used poplar moldings to replace maple moldings at a factory I worked at once. The wood was getting stained fairly dark so the look was very close and the poplar stayed straighter than the maple and was much easier to bend into place than the maple. Some of the larger crown type moldings couldn't be forced into place if they were maple but the poplar ones could. It is a soft wood for hardwood, machines easily, takes pretty good detail, and sands fairly smooth. It's only two drawbacks that prevent it from being more popular are the softness and lack of character. The Canadian prairie provinces have an abundant supply that most of is being used to make Oriented Strand Board.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.