Bevan,
I think Jacob said he's using OEM struts with his WhiteLines and he's very happy with the combo. From what I recall the springs are 20-25% stiffer than stock, but if you'll look at the comparison pics with stock they appear to be progressively wound, with more coils, especially in the rear (load capacity?) and although they ride more firmly I don't find them objectionable even with the car empty save front seat occupants. I don't believe you would regret trying them out!
Glenn O