what is involved in putting an irs in my 60 kg can anyone help still learning all this vw business and is the cost of converting it to disc brakes ridiiculos

You will have to source and weld the chassis mounts (pivots) for the trailing arms to teh rare section of the chassis and change gearbox, spring plates, torsion bars, driveshafts and hubs. It is a 'body off' job and to be honest, if you have to ask, it is beyond your ability at this stage!

Disc brakes - are your stocker drums rebuilt and as good as they can be? Second-hand conversion 'kits' come up every now and then. Do you wish to stay with the 5-stud whees or convert to the later-model four stud?