Eibach sportlines should only drop it approximately 40mm, the Prokits are 30mm. I know this as im currently running sportlines myself.
Drops of up to 40mm are fine with standard length shocks, anything more is too much for them to cope with and should really have uprated and shortened shocks/struts.
I've got Weitec shortened ones with my Eibach but if your standard boge ones are still healthly then I'd go for it.
It's worth changing the top mounts whilst you're doing them as well for piece of mind.