wardy, id say stay with the stock struts or go for r31

the problem though with going r31 is that it will limit your wheel choice as you wont be able to too much of an offset on the rims without them being outside the guard...so less dish

where as stock struts you can keep the original track width...but if you then do the silvia brake conversion using disc hubs the track will increase anyway. but if you do the conversion and make it work with drum hubs then you should be pretty close to stock track width and be able to use neg offset wheels without them sticking out the guards too much