1. you can almost certainly use the JJ EL-34s.
2. you can order an "integrated quad" of 2x6L6 + 2xEL34 that will all run on EL-34 bias setting on your roadster, from Eurotubes. It is a great sound using both types of tubes. (you can also get E34Ls, KT77s, 6V6s that will also run in the...