looking for head unit/speaker suggestions

I will soon be getting a 2001 toyota highlander with a broken head unit and thoroughly mediocre stock speakers, so I am looking around for viable replacements. I am a broke college student, so I would like to keep it as low cost as possible, but I drive a lot and good sounding audio is very important to me. I have a 4 channel amplifier (Kenwood KAC-X40) and a 500W mono amp with subwoofer (Kenwood but no model numbers at the moment, though they are about 3 years old at this point) in my current vehicle, which I will be moving over. Unfortunately, all my current speakers are different dimensions and my current head unit has enough flaws that I would like a replacement. Therefore, I turn to wisdom of the masses to see what the most viable option might be. Here is a list of my general requirements for a head unit: 1) 6RCA outputs (Front, rear, and subwoofer), but I am not particular about output levels. My amp will take anything from 2-4V pretty well for sure, and I would expect it could handle a wider range with ease. 2) Bluetooth capability for both phone calls and streaming music, preferably capable of multiple devices easily, includes a microphone with good call quality. Must support Android phones, as my research has led me to believe that most are designed for iPhones and have less compatibility with Android phones. 3) Ideally I would like 2xUSB and 1x3.5mm inputs, with one USB in back for my iPod Touch and the other two in front, however I am not completely set on that. I do require at least 1xUSB and 1x3.5mm though. 4) The ability to control a connected iPod either through the head unit itself, or from the iPod while still connected. I got my current head unit just before this feature became commonplace and it is the biggest reason I will not be keeping it. 5) The opening is a double DIN, but unless a particular double DIN unit has all the features at a better price point, I would prefer a single DIN unit. As for the speakers, I believe that the Highlander has 1-1/2" tweeters and 6" 3-hole door speakers in front, and 5-1/4" 3-hole door speakers in back. My amp can drive 70W RMS into each channel at 4 ohms, or 100W RMS into each at 2 ohms. I have no particular preference for brand, impedance, or specific frequency responses in the front crossover. I need something that will fit the size, sound great, and not get destroyed in the event someone overdrives my amp. BTW, my general choice in music is mostly rock, ska, punk, and a little metal. Ideally I would like to spend less than $500 on a head unit and speakers, but I do not know if that is entirely realistic. From what I have seen, most head units with my desired specs will be $200+, and speakers seem to be $90+ a piece. Any suggestions you have for both what to buy and where to buy them would be greatly appreciated. I apologize for the length of the post, but for those of you who read the whole thing, I applaud you. I like to put forth as much information I can to make it easier for you to help me.

JVC KD-R820BT. has pretty much everything you are asking for. i know from experience that this is a very good quality radio, as are most of JVC head units. the only thing that is sometimes not compatible would be audio streaming through bluetooth, it took me a while to figure out how to do it on my JVC kd-avx77 but mine is almost 2 years old now and the 820 is brand new so it should work a little better.

Thank you for the quick response and for a great suggestion. I looked into that head unit and as you said, it seems to fulfill all of my requirements. All the reviews I could find of it online indicated that it is a very good unit, the bluetooth works well, etc. If anyone here has had any experience with this head unit, I would love to hear your opinions as well. As far as speakers go, I've continued to look around and stumbled upon two sets of speakers. The Kenwood KFC-P709PS and Sony Xplod XS-GTX1641. The only thing I have to go on are reviews, but they both seem to be reasonable good speakers. The Kenwoods are a woofer and a tweeter for the front, while the Sonys are a 4-way coaxial setup for the back doors. I do not know if a 2-way system up front is sufficient, or if a 3-way would be better, and I don't know if a 4-way is overkill for the back (as I am never going to sit back there), but most importantly I don't know how good either of these sound. Thankfully I realized I was mistaken earlier, in that most speakers are $90+ for a pair, and not a piece, which eases my budgetary concerns a bit. However, I would still like to find the best sets of speakers I can for about $100 a pair.

the number of "ways" a speaker has is mostly just a gimmick. anything more than 3-way coaxial to me is just ridiculous. you can have a 10-way speaker but each of those speakers will be so small that it doesnt matter.

do yourself a favor and keep away from the sony xplods. any decent set of speakers should cost you about $100 but at the same time just because it costs money doesnt mean its worth what you are paying.  i would stay with as few "ways" per speaker as possible, 2-way minimum 3-way max. if you dont plan on buying an amp then i would get a set that handles about 50 watts per speaker and do your best to keep the front and back speakers the same brand and series.

as for what sounds good, no one can tell you what sounds good but you. go to some stores and listen to some different sets of speakers. bring a cd or an ipod with music you like on it and ask the sales guy to hook it up to the demo.

consider a kenwood 848u. all the features you asked for plus built in crossover for the front rear and sub.As far as speakers go, we have been selling a lot of MTX and Rockford coax and separates with great results.