I would vote ms-8 with the dls r4 (which you may have to top mount). Still waiting to hear back from quiksr20 who has been working just such a package.
FS:Sub Amp - works w/ Technic harness! MRD-M300 - cheap
DON'T BUY FROM RAF555!!!! Promised fix! - strung me along til Paypal dispute period expired!