We're not selling Giroud anytime soon so I agree we have to be very smart about integrating a new striker. No point having another good but not class striker, but if we trump Giroud I can see his form/confidence dipping quickly.
Its a tough decision, but eventually we have to choose who's strengths to maximize - Ozil or Giroud. Really don't see those two becoming a great partnership as Giroud (and Santi/Wilshere/etc.) are clogging space for Ozil rather than making it.
So, I'd prefer a more mobile striker than Giroud of which Benteke and Michu are. Just not sure either is that significant of an improvement. With time, and belief in what we can achieve, my opposition to Suarez has waned. Throw Liverpool a 50 million offer in Christmas (hopefully they're waning by then) and see if they bite.