Well out of those two I'd take the Alpine but I'm biased because I love Alpine HU's. I have a 9886 in my car right now and love it...Looks like there's a lot of ebay "Buy It Now" listings for the 9883 for only $100 and those are usually the MAX price of something so you may be able to talk him down a bit. Is the guy selling it on ebay or on a forum or what? Can you send him an offer?
he is on CL. I am still searching. I want the best I can for $100-$200. I am not really a fan of deck that have to flip down to insert CD. I like slot faced decks. have a WTB thread going on if you know someone selling