Yes, I want to make the Whirlwind. The extra sets of heads, I bought just for the reasons you mention. (Already trashed one while trying to press home the valve bushings). They come with the possibility of having both ports at the rear, or one at the rear and one at the side. Also when I bought them, it looked like KEO himself was not going to continue making them (he's over 80). But now it seems his nephew will continue offering them.
We are 4 in our club that bought the castings, all of us with too many projects already. So the noise will not be deafening for some time yet. One of the guys have a wire EDM in his basement, so if there are chances of selling some rockers, rods and maybe gear wheels, that may reshuffle his priorities.
The gear wheels are available commercially, but quite expensive at around $3-400 for all of them.