I purchased some nylon bushes for my 205-Mi16 from MotorsportParts in the UK: website here
After doing the rest of the suspension mods - springs/shocks and with the stiff swaybars and torsion beam, we actually decided not to put them in as:
a) some of them require dismantling a fair amount of the suspension and;
b) my suspension is already pretty hard and I still want to use my car as a daily driver
If you do decide to go down that path, I have heard that nolathane bushes are pretty good - not sure where you'd source some for a 205 though - perhaps demon-tweeks?
This is only my opinion so you might want to ask some of the other 205 guys that use them for the track