Bro,
Why you spending on 2 x pairs of rears...?
No front stage...?
That will be a stupidity!
Buy those Infinity reference 6x9 speakers for rears...And get Pioneer D1720c components (Around 9.5K) for front instead of spending on a pair of Sony 6x9 speakers...
At-least,Buy Kenwood M845 or its new model,for feeding your comps along with your infinity 6x9....!(Around 9K)
For,Pre you can get Pioneer 9350sd,if you more into usb.....Else,Pioneer 8850mp,8650mp,9850bt any day over Pioneer new crap range...!
Get any good branded 4awg power wiring like (Fusion 4awg,Stinger 4awg,Streetwires 4awg) for Kenwood amp...!
If you are on less budget than don't spend on sub at the moment....!
Get a mono amp later and spend on a sub.....Single or Dual subs,According to your listening preference and taste...!
Regards!