Well again I can only tell you which one I like better which is the Bostons, you should listen to them yourself somewhere before spending a lot of money and being unsatisfied. Between the two choices the MB Quarts are not like they used to be for sure, and the Bostons do sound clear but they are also designed more for a very flat response what that means is a fairly dull lifeless tweeter and lack of midbass, again this is opinion. If you are looking to get a fair amount of midbass from your components I would keep looking for different brands to choose from, maybe Memphis M-class or Polk Momo or something there are plenty out there that have stronger mids in that same price range.
The main problem for now is your factory setup, so to make everything work properly together you need to either wait on installing the speakers until you get the radio and amp, or if you do not want to wait you need to get component sets for the front and the rear. For now you will just need to use the wires provided by the factory, and not use your crossovers until you change the amp and radio, and then at that point you will have to install the crossovers (the easiest way is at the location of the factory amp) because without any crossovers the speakers will sound very badly and blow very quickly, but like I said for now the factory amp has crossovers.