Which pre should I choose?

Vintage gear does not "need repair constantly ". In fact it is probably better made than most modern units.  As long as any electrolytic caps are replaced you should be good to go. 

analogluvr: Tks for your opinion. One of my friend also suggests me to choose a good solid state Pre. from famous brand for the longer life than the tube one.  What I care is once the vintage has problem, whether I can get it repair and recover.......... (according to the opinion of one audio service engineer, some times, too old gear might hard to find parts which had been produced long time 20~30 years ago.

faust168-

Consult Accuphase  for parts/service on those older pre-amps prior to any buying.  Those prices are on the high side for vintage pieces as well.

Keep me posted & Happy Listening!

I agree with the suggestion for a tube preamp. It has been the single biggest improvement in my system. I can't speak to the "accuracy" of the sound, but the increased warmth made me want to listen longer than with a solid state unit.

faust168  said..."Aolmrd 1241: Tks for your suggestions. I am afraid the vintage gear will always need repair constantly. It will cost your time and money and inconvenience. Also, I have heard that Tube amp. is not as durable as transister one."

I thought you were interested in vintage gear since you mentioned that the SS preamps you were interested in were up to 24 years old. With that said... try to audition a Primaluna Dialogue Premium preamp. I own one, and it rocks!  Lots of info on line.