What about the PCC?
Also authorized was $4 million to TriMet in support of building a prototype streetcar in the United States
How about one of these?
The PCC might be an old design, but it's
- more attractive than the angular lines of the Astras or the SD600s
- lighter than either of them
- A proven design with thousands of the vehicles put into operation in the United States, Europe, Asia, and Africa.
- Durable; New Jersey operated their fleet of PCCs for fifty years before replacing them with slow and heavy modern cars sometime around 2001.
- An easily licensable design (and maybe even royalty-free by now; it's been several decades since a PCC was last built, and I don't think patents have suffered from the Disney effect.)
- has a railfan seat.
The only disadvantage I can see about the PCC is that it's not a lowfloor car, and even that might be a surmountable opportunity. Several of the European operations that operate PCCs have also modified them for modern service (Sarajevo, prior to the spectacular disassembly of Yugoslavia, rebuilt some of their ex-Washington PCC cars into articulated units) and there's certainly nothing keeping the City of Portland from taking advantage of Europe not being stupid enough to let their homegrown trolley industry die.
I'd suspect you could take some of that US$4 million to hire a mechanical engineer to design a fishbelly into a standard PCC. Modern electronics are smaller than electronics the PCC was designed for, so you might be able to get away with pushing them outboard of the trucks and leaving a sunken section at the middle of the car.
(hat tip to AboutItAll for the link to the PDF document)