Please advise on A/C conversion

[Zsolt Kovacs]

It is time for me to swap my A/C to R123 since it doesn't work and R12
is illegal now. I have been reading the archives and found conflicting
answers regarding what I need to replace. Some people recommend to
replace only the gaskets, hoses, oil and fill the system, some also
suggest to replace the dryer and retrofit the compressor.

Any BTDT? Please advise.

Thanks,
  Zsolt