A post tweed Fender amp with reverb and vibrato (generally a Twin, but any that can get the big clean sound - sometimes the right Deluxe is better for this on tape). Reissue Jensens of VST speakers prefered.
A Marshall amp, generally 100 watt, with EL-34's. Not later than JCM-800 series, with the possible exception of the 30th Anniversary models. 4-12 cab w/ Greenbacks or Vintage 30's (or two cabs loaded with older alnicos - yummy), the older the cab, the better.
Ampeg B-12 or B-15. Or SVT, but I find the first two easier to work with.
Those are your basics. Added points for a EL-84 Vox or derivative (Matchless, Bruno, legions of others), and a Hiwatt Custom amp, preferably with a Fane loaded 412. Small amps are good, too, like Champs and all the offbrand vintage things that resemble them (Supro, Rickenbacker, Silvertone, Gibson, etc.) - pawn shop scores, basically.
If we're really in high end here, I'm assuming access to gear hire that'll have more specialty models, like rare vintage amps and high gain high end models like Bogner, VHT, Dumble, and so forth. If you can't hire it, you better have the bucks to keep enough variety around to keep the clients happy. The cheaper alternative is to supplement a basic amp collection with a variety of higher end distortion pedals. But that's another thread.
Bear