Grp4 rear turret shocks

[Frayer]

I am choosing the best shocks for my E36 compact intended for gravel rallyes. Are grp4 turret shocks really the best value for money, not going the coilover way?

And most important, do they fit onto E36 compact without modification or the modification of turrets ist a must, because I know they are wider then standards Bilsteins.