dave, from what i learned from working on the model t wheel, the structural woodwork for the bodies were pretty much oak, and i cannot stress highly enough, the spokes for the wheels were hickory, and only hickory. it has both the strength and needed flexibility for this. oak, whether red or white, has a bad habit of shearing across the grain when used for spokes, and i have seen several pics of what happens after they shear. once one spoke goes, you lose the integral strength of the wheel, and the other spokes near the one that failed will also fail, and the wheel will seperate from the hub, and that's at a good walking speed. if they want oak spokes, convince them otherwise. if they won't be convinced, walk away from them.
if you will be turning the spokes, here's what i learned. the angle cuts at the hub are 15 degrees, the tenon diameter for the one i rebuilt was 1/2" diameter, by 1/2" long. what i would do differently on another one, measure length of the turned body of the spoke from 1/16" in from the hub end, i measured from the overall end, and got burned short on the rim end, i would also make the turning blank about 1/16" wider, to eliminate the slight gaps that i encountered, not that noticable, but still too much to be used on a car.
another thing i learned along the way, there are 2 different types of wheels. demountable, and non-demountable. the non-demountable wheels have wooden felloes, into which the spokes are pressed into, fitted into the rim, and the rim is heat shrunk onto the felloe. you can see the process in the film footage of ford's model t assembly lines. it is called non-demountable because you have to take the entire wheel off the axle to change the tire. the demountable wheels have a metal felloe (which is the one i have), and the spokes are press fitted, along with the hub, into the metal felloe for a very tight fit. that is why the blanks should be a little oversized for this fit. then the felloe/hub/spoke assembly is fitted to the actual rim, and secured with 4 bolts. with this type of wheel, all you need do is undo the bolts, and remove the rim/tire from the rest of the wheel, no need to take it off the axle.
if you are going to be getting into the wheels, i can send you the info on making a wheel spoke press like the one i used.