There is loads to consider. and i mean loads
If you are just considering the right size wheel you need to look at the wheel width as well as the offset they both go hand in hand.
then there is the bolt pattern. You need a PCD of 112 although you can make others fit with wobble bolts.
To make the correct decision you have to consider how you are going to drive the car and how low you are going take the suspension.
If you are not going to push the car on corners then you can get away with a low car and a low offset but whats the point of having a ED 30 then.
My advice would be to try and stay as near to 51 offset with a 7.5 or 8.0j wheel as you can the wider you go the more pain you will have.