I used a kappa perfect 12, I thought it was a great sub for the price. I think you can get them on ebay for ~100-150.
As far as components my suggestion would be to go and listen to as many as you can. If you like the way that quarts sound you might want to look for something with a metal tweeter.
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Ill say i go by His and Al's thoery of "Your getting sprayed" Doesnt matter what it is. Grandma in the 1982 LTD is gettin the bottle.