40mm lower spring which shocks?

[tommycon45]

this as probably asked loads of times but here i go,, got myself some 40mm lowering springs and would like to know if i can use them with the original struts front and rear or do i need to get lowered ones??? i do know one of the rear ones is abit suspected and seam to be leaking so will need new set for the back but should i buy lowered or standard???
cheers.