Yeah, you can't get Bosch plugs that are non resistor any more. I have a few left but will have to switch to NGK this year.
The books usually state W7DC for most of the older cars but found that they were too cold for just about every aplication. I switched to W9DC and they worked much better. Based on that I would get the BP5ES.

A rough idle or miss that can't be traced is often bad plug wires. Some new sets will have a carbon coil wire. Chuck that in the garbage. You want solid wire all the way with 1K ohm spark plug terminals.
Most rotors have 5K ohms, the connectors at the distrbutor cap have 1K as do the coil wire ends and spark plug ends. That's at least 10K before any voltage hits the spark plug. On older points coil systems with 16KV ( black ) coils that doesn't leave much to work with.
On those older engines I try and remove all resistors in the system except the spark plug terminals.