What the best 6.5" Coaxial Speakers to get for my back doors in my 1999 GMC Suburban in the $100.00-150 price range and would it be best to amp them or just run them off of the headunit
Look into products from Boston, JL, Alpine, or Pioneer. It is ALWAYS better to amp your speakers, headunit power sucks //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif
While it might be "best" to run them off a seperate amp, it is a huge waste of money in most cases. I say this because rear fill, if used, is usually only faded enough to barely hear. At those levels, deck power is usually more than sufficient.