Re: 8400bh vs 8053 eclipse.
I believe you have to use it with the "Eclipse Commander"....that's if my memory serves me right. That is a very nice SQ geared HU. I think it also has an auxillary input.
It depends on what you really want out of your system, and which head unit will help you get there. Take a close look at this, then weigh the pros and cons of both HU's.
Alpine: PXA -H600
Alpine: CHA-S624, KCA-420i, KCA-410C
Rainbow: CS 265 Profi Phase Plug
Rainbow: SL 165
ARC Audio: 4150-XXK
ARC Audio: 1500V1-XXK
JL Audio: 10W6v2 (x2)