I'm betting the Boston's with the JL amp would sound pretty darn good. I experimented alot with a previous vehicle and would have to echo the "sick of multiple amps" comment. I had a 97 Saab 900 with CDT 6.5's in the doors, a stagefront kit on the dash, a 12" Elemental Designs sub, and an Alpine MRV-F545 running it all (125x2,500x1). Sounded awesome!

So far I have only added a sub and amp to my X5 (Diamond audio 10" + 400 rms). I plan to upgrade speakers in the future as the stock speakers sound like pooh. The sub is a MUST.

Try the Boston's and let us all know, otherwise the BSW seems to be a good plug and play option.

__________________
2004 BMW X5 3.0i - Mine
2011 BMW 328i xDrive - Hers
2002 BMW 325xi - waiting for a new owner