Why don't you just break out the old torch and some 1/4in. plate and make your own. If you don't have a torch make some cardboard patterns and go see your frendly welding shop. While you are there they would be happy to weld them for you.
You would probably be suprised to find out that most people who weld these types of things up have no formal education, training or testing for welding on production line stuff anyway. Most just got better over time. If you really feel the need to gusset the spindles, just do it local.
The reason I am going down this road is when I bought my Thing front end for my Class 11 bug, I didn't get the tie rods. Since I needed tie rods anyway, I went with aftermarket 1" alum tie rods.
IF the alum tie rods are all that in strength, a problem from offroad abuse would either show up as broken tie rod ends, or a bent spindle steering arm.
I can carry spare tie rod ends if the spindle arm is less likely to have a problem in the field.
So you think your project is taking forever eh? Well you've got nothing on me.....