Hi,
I did a search for some rare parts and came across Utsource. They could be a good source for the "expensive" V9990 VDP: V9990 I hope, it is the correct V9990 (Yamahas VDP).
In addition they have the CPU, the DUART, the PI/T, the RGB encoder, the RTC, the ethernet controller, the CPLD and the VRAMs.
As for the SIDs, one has to resurrect them from a dead C64. Maybe a SwinSID can be used as drop-in replacement.
Simon