Mr Singh i may know someone who will want that set up soon.
I have heard this Gladen set in Mr Singhs car and i think it would be wrong to go for L7 or Alpine routes. Like Mr Singh has said the bass on those kits isn't great. When i heard the Gladens i was really impressed, the woofers played really low and i think that was without any EQ or anything IIRC.
2008 E92 335D SE
2010 E90 320D SE
1994 E36 318I SE
1996 E36 316I SE