I am running a long axle on the passenger side, and do not have the intermediate shaft so I did not have to fabricate anything for that to work. I would check the Fiero groups to see how they have fabricated theirs as it's a common enough thing in the Fiero world to add the intermediate shaft.
Me getting an axle made cost me $100 Canadian. I provided the inner and outer tulips, they found a Honda Accord axle that was the same length and used the same spline counts and put it all together for me. Cheaper than the relocation kit, and it works!