If you mean the main mounting bushes then noone makes them, there have been some custom ones made in the past and iirc vssirvine is doing some testing with a set designed for a skyline so might be worth a pm.
Whiteline do a align and lock kit which will take the play out of the rubber bushes, but if your bushes are knackered then this wont cure your problem it will just hide it for a while.
The other option is a second hand subframe, most of the breakers find these difficult to sell so you will be able to pick one up for peanuts.