Obviously I want headroom, first and foremost, so I guess that translates into higher wattage. But I'm thinking that 40 watts might give enough clean headroom for the volume I need. I've read that a lot of old jazz records used a DR, but that maybe a Vibroverb would be a better choice with the 15 (not that I can really afford one). What about the Pro Reverb for jazz? It seems to be the most affordable and some say the best sounding of all.