Depends how much you want to lower it by. You dont want to get alloys and then leave it at standard hight it would look like a 4X4 and you dont want that. The best thing to do is lower it first and then have a look at wheels after, then you will be able to judge the size you want. The car will handle alot better if you lower it and then put on a reasonable size wheel. The wheels will look biger if you lower it as well so 15s will look very good