VE Amp options - 1 or 2 & how many channels??

[Calais57]

I have read everything I can find about upgrading the VE sound systems. Plenty of great info but I can't find answers to my amp questions.

My system upgrade so far (fronts installed and the rest is yet to go in):
- Front: Hertz ESK 165 components (splits) RMS-100W (4 Ohm).
- Centre speaker: removed
(Very good improvement is noticeable up to this point but not fantastic)

- Rear Doors: Hertz ECX Coax RMS-70W (4 Ohm)
- Subs: 2 of the Kicker 8" (10CVT82) RMS 200W (2 Ohm). I am told that to run subs in-shelf "Free to Air" that they should only be powered to about half to 3/4 of there RMS power rating.
- Dynamat Extreme for rear shelf and doors

Criteria for choices:
- low/mid level upgrade to keep costs down (but still way better than stock)
- boot space is critical (often full and need to use back seat as well)
- do LOTS of country kms & need spare so can't use that space for a sub.
- unlike a lot of you young blokes (or young at heart/ears), I rarely would have the sound system above about 20 in volume. Usually below about 16.
- I want the rich LOW VOLUME sound with decent base that I am told is available only via amplified speakers and subs.

Questions:
- Is a small 1 or 2 channel amp for the subs enough
- I don't think it will be, so should I go with a 4 channel for speakers AND a separate 2 channel for subs
- OR is it better to go for a 5 channel straight up?
- Would the 5th channel on a 5 channel drive both small 2 Ohm subs?
- ANY other comments/recommendations very welcome - even to tell me I have made wrong choices if necessary!!!

Thanks!!

[Calais57]

OK - have had suggestions today that a single 5 channel would be better/ easier etc but that they can be large in size.

Any suggestions about good 5 channel amps to drive
- Front: Hertz ESK 165 components (splits) RMS-100W (4 Ohm).
- Rear Doors: Hertz ECX Coax RMS-70W (4 Ohm)
- Subs: 2 of the Kicker 8" (10CVT82) RMS 200W (2 Ohm). I am told that to run subs in-shelf "Free to Air" that they should only be powered to about half to 3/4 of there RMS power rating.

Thanks