OP... so you don't know how to install a car stereo? Keep in mind that you're getting these advices from random people on the internet and if something goes wrong/defective then it is really hard for anyone on the net to troubleshoot, that is if they even bother to help when things go sour. Do you know how to set the gain on the amplifier along with the EQ/volume on your headunit? Do you know how to run wires in your car without interference? Do you know how to properly tighten/crimp every connection so they don't come loose overtime? Do you understand voltage drop and what a hot coil smells like? Do you know what to do if you get alternator whine in your audio signal? Does you current car's electrical system in good enough shape to have a stereo without your car acting up?
^^^Those are questions that haven't been asked by anyone here, because they don't really care, they just want to throw their favorite brand to you like a fat kid pointing at a chocolate cake. I want to tell you to just visit a local stereo shop and have them do it all, that way you get warranty and if something goes wrong it's not your problem. However $700 isn't going to get you everything, you'll need at least $1000. Also shops don't warranty anything if you bring in your own equipment to have them install it (just like car repair shops) so if it's defective then you just paid money for nothing and you're now stuck with a broken product that costs money and time to return.