Those springs were made by Eibach for the 160SR specifically as the spring rates are different. IIRC the ride height is slightly lower too, don't quote me though.
Personally I wouldn't mess with spacers, not sure what it'd do to the handling but you'd mullah wheel bearings! I quite like the way the rear wheels are slightly in the arches, my only complaint is the back sits a little high.
The car is for sale if you're interested.
The strutbrace-I thought about getting one but the suspension turrets are so close to the firewall I don't think it'd make much difference. I reckon it could do with some stiffer ARB's and possibly a rear brace though.