A Fowler, using wads and shot, needs far less force to load than a rifle, so you might be fine with an Oak ramrod/wiping stick, if you haven’t access to a better hickory one.
(If however you plan on loading a patched round ball, the Oak might not work out as well unless you have one with a perfect grain.)
If you decide to order a good quality
ramrod then get a few. The extras may be needed somewhere down the road.