AlterKtion - True Pro-Touring Suspension

Actually, the more I think about it, the more I think anti-dive wouldnt matter much on the street, just because most people dont stress a car enough to matter on a public road.

With a 17" rim, 8" wide/5.70bs is about the limit to clear the tie rod and fender, which I like to mate with a tire less than a 10" section width. So 9.X section is about the widest. On an 18" rim, there's alot more room to the tie rod when turning, so you can go to a 9" rim with around 6.3bs - On an a-body. The B and E cars cant do this because the upper arm is wider and the front a-arm leg hits the 9" rim. On my Dart I'm using the mustang rims - 18X9 in the front, and I did actually fit a 285/35/18 on it. But the tire touched the frame rails by 1/4" when fully turned and it was really close to the fender. So I kept the rim and went down to a 255/35 - I want lots of clearance for those railroad tracks :)
A 275/35 might not be too bad, but still tight.

And you're right Top Heavy, springs are fairly cheap and easy to swap out on a coil over. Even with lighter springs, the car would be respectable, the heavier springs is getting down to little details and hundreths on a stopwatch. I'd normally go with 450's on your car, but you could do 500's and still be in good shape.
Sounds like a fun car, and there's really only two things I'd mention based on experience/opinion. First, definitely do power rack - the manual racks are ok with drag-type skinnies, but once you have more than 5 or 6" of tread on the ground, it's an absolute bear to steer in parking lots. The power rack also has a better turning radius than manual, which makes a fairly big difference in parking lots.
The other item is informational only, but I had race-weight hood and fenders on my car for years with dzus fasteners all around - they looked awful in the sun because the heat would warp them. I then switched to a heavier bolt-on glass AAR hood and metal fenders - it turned out the weight difference was only 25lbs total and it looked far better. Of course, every pound makes a difference, so thats a personal choice thing.

On the uppers, I make the arms to accomodate the steeper upward angle of the balljoint, so it works fine.
Concerning geometry on the same issue, again, it depends on suspension design. Alot of stock or homemade suspension has poor geometry, so the idea is to level the a-arms and tie rods at ride height(center of the arcs) so you have the most possible travel up and down before the geometry starts to get ugly. Leveling the a-arms is simply the best way to make the most of a bad design. But if the design has favorable angles throughout its travel range, your only concern is to set the desired ride height prior to wheel alignment.

...we can chat on the phone when you like, but I'm happy to keep typing in the meantime :)