im a newbie and i was looking up speakers for the front speakers 6.5 and my back speakers 6x9. I do not know alot of brands that are good but so far ive been told to look up alpine and kenwood. And i came across: Alpine SPS-170A 6.5 & Alpine SPS-690A 6x9 and Kenwood KFC-1689ie 6.5/6.75 & Kenwood KFC-6999ie. I was wondering what else would be excellent kinds of speakers. And would i need amplifiers for these speakers to produce better music? Thanks