holley 700/750 double pumper VS holley 870 street avenger carbureators!!!!!!!

ok everybody i've gotten a combo down that i'm wanting to put on the 460 i am planning on putting in. the 460 will have:

*d0ve heads
*280h cam
*stealth manifold
*shorty hedder w/ 3' exhaust
*2500 stall
*c6 trans

what will work best with this application the 700/750 double pumper or the street avenger 870. the 870 is about 420 bucks while the double pumpers arae only 320 for the 700dp and 370 for the 750dp. the 700dp would probably be desirable because it would probably give the best mileaage and still the the double pumper effect.

which is preferred by all of you if you were in my situation? i want this 460 to be very street mannered and still get decent miles to the galloon. another option would be the street avenger 770 for about 380 bucks.