I would like to know if it is possible to change several parts of my 1999 Jaguar S type 3.0 v6 for other 2.7d models or the R type.
The parts I want to change are the following:

bonnet
front and rear bumper
all the doors

Then I would send it to paint and it would look spectacular and how I like it.

 

Unlikely / no.

I'd spend the money on rubber/plastic/etc parts (suspension, cooling, etc), they're all very old.