Playing with the idea of upgrading my front speakers...

[Accord Man]

Trev, No you will not damage the speakers by driving them off your HU. As long as you dont play it to the point(and beyond) of distorsion, everything will be fine! Promise!

You really dont need a 4ch amp. The back speakers are just their to fill your environment with sound.. kinda like backup what the fronts dont cover.. But what you should be hearing/listening to are the fronts.
On a side note, many SQ competitors dont power the rear speakers.

Also you really dont need a Nak, Mac, Helix, Brax, Arc, Zapco...bla bla bla.. Unless your a total SQ fan or competitor, dont waste your money.. Look into Kenwood, Pioneer & Autotek..
Oh by the way Autotek sells for not too expensive, but is a very good product (high quality and reliable).