A little help...

So here is the story,

I just bought a 2013 Honda Accord Sport and I started to do a little research on upgrading my speakers...that's when the sickness began!

I am interested in a SQ setup

So here is what I have so far:
HAT Unity U61-2 (6.5" 2 way)
NVX Sound Dampening

Here is what I am considering:
A single Dayton RSS265HO-4 10" Reference HO subwoofer 4 Ohm in a sealed enclosure

I would like to use the stock head unit and rear speakers as fill.

Here is what I am looking for:
- Advice on a 5 channel amp vs a 4 channel and a mono amp? (Budget $200-$350)
- I've been looking at the ppi900.4 and the SS Ref4.760 Any thoughts on those?
- I was planning on going passive with the Unity's but would an MS-8 going active be very beneficial for my setup?

Any suggestions would help, thanks!