If you ever get a starter that actaully fits, and it goes bad, rebuild it yourself. The primary wear parts in any starter are the brushes. You can get a set for 7 bucks and they shouldn't be too hard to replace if you know how to solder (but most people don't).

Or, classic industries sells genuine GM rebuilt starters for $100, and I am sure the quality there is better than Napa or any other parts house.