316/318 sump, how low to go?

[olie30g]

Hi all, after reading experienced views on here on coilies im opting out of buying a set as i was planning to, but this now leaves me with questions "/
Do i go Bilstein or AP?
M42b18 engine, 4door, 16" wheels dont fit yet but arches are getting molested.
Can anyone tell me how low can i go at the front, and keep my sump? (iv smashed one off learning to drive the car) First rwd and that ")
And if i lower the front say 60, and the back 60, will it look crap compared to 60/50?
Thanks if u can help