I personally would go with MB Quart speakers. They have great quality sound and are pretty sturdy.
They are a bit pricey, but with research I'm sure you can find a good deal on Ebay.
I think, if I'm not mistaken, that you would need 2 of the 6.5" and 2 of the 4". Get separate tweeters since the MBQ tweeters blew on me a few times. Other than that they were amazing.