That elm and hackberry seem like the place to start. One of my favorite staves to find is a clear, straight split, 68" long or more, from a 5" dia. hard "white" elm sapling.
Honey locust will make a bow, but has lots of issues and is mediocre to decent at best. Heartwood sure is pretty, though.
If you cut a branch or sapling you can take a bow from the upside, or the downside, in my experience. Most people I've heard say, say they prefer the upside, as it often dries into nice reflex and has favorable growth ring thickness.
If you try taking a stave from the side of a leaning tree instead of top and bottom, you will have nightmares.