Brucer,
The solid bar idea would be a lot of work like you say, but the ibeam look would be interesting. I think I saw a ratrod with some kind of early tractor tapered ibeam radius rods before at a show. He had drilled a bunch of holes down the middle of the center web. It was actually cool looking. It's an interesting idea, but I'm going for the traditional wishbone look, and like Ron says above, the tubing is much lighter and mucho strong enough.
I also like your idea of a slot. I've seen a traditional wishbone slotted up front so the steering arm can pass right through the middle of the wishbone arm. With my design having the heavier center web running down the middle of the bar, you could do something like that without sacrificing much strength. Maybe I should think about doing some kind of slot like you mention... Hmmm. I'll just leave it as an option. I still have no idea yet where my components will be running.
One of the things I'm preparing for with these front bones is how I'm going to support the front of the car. I've seen cars where the spring perches are attached to the sides of the wishbone to support the front. Because I'm going to try and run an early Hemi, I need to be careful/concerned about the extra weight. For the look I'm after, I would like to see a traditional ibeam out front, then the radiator tucked low just behind it. Rather than using a traditional suicide spring up front, I might try using some kind of hollow torsion bar set-up with some cool looking drilled arms that link-up somehow to the wishbones just behind the radiator. I need to think more about this idea. I'm not sure yet if I can make it look good.
The torsion bar idea comes from being able to easily adjust spring rate, and ride height. I've built and used torsion bars on other cars before (sadly not any rods, but race cars). Ride height as you know is adjusted at the back with a small arm, and spring rate is easily adjusted by changing the O.D. of the bar. In the past, I would make and heat treat a bar that I know is a little too stiff. I install it, and if I need something a little softer, I just turn down the O.D. in very small increments until I get the desired spring rate. You can also change the spring rate by adjusting the length of the arm, or the length of the bar. By making the bars hollow, they don't weigh a ton.
Anywho, just thinking out loud. I bet for all the time it takes to design and build a car from scratch, 3/4's of that time is spent just thinking about it.
Thanks for the ideas! Take care,
David
Of course, the ibeam will be drilled. Because I can do that! 
