i have a set of pretty good mb quart speakers from before they were sold to maxx sonics (which is in lake zurich)
i loooove them. titanium dome tweeters... they were a good chunk of change, but have moved with me in two cars... and sound incredible. my gtp actually only has the mbquart component set up front, and then 1 sub in the trunk... id put it up against most stereos as far as sound quality goes, especially when it gets loud.
but yeah, OP. get a good head unit, good 4 channel amp to amp your speakers so they can actually get teh power they need and crank it up.
new focal stuff is $$$$ but