Lloydelees third alternative should be seriously considered if resale value is of concern. Even though Bill Thalmann and Bob Backert are both accomplished technicians whose cj mods are well reviewed, the amp can only be considered a pure cj if cj does the work. That, IMO, should add to resale value. In my conversations with Bill and Bob, I came away with the impression that Bobs mods were somewhat more invasive - not to say that the result isnt stunning.
At this point, I would suggest that you develop a very precise set of objectives, and without initially disclosing those objectives, determine through your interviews which guy most shares your values - if he hears like you hear, he will do a better job.