Whats the ideal cd player to tube modify it? Essential instructions.

I always wanted to try and modify an early philps chipped and philips transport cd player and add tubes to it by a qualified tech. What should i make sure is done properly by the tech i use. Any ideal specific tubes to be used? How about Teac vrds transport used?
instead of such suffering, you can get Musical Fidelity tube buffer and add to any CD-player you wish.