its the icold start advance control, you will want to remove it with the 14mm cause if it blows it might lodge some plastic pieces in the head (usually fails with stock injectors with the pump maxed guessin its a case pressure thing but ive never had one hooked up).
6x18 arnt the Minimum, they are probably the max you would want to run with a street driver.
the afc will not NEED to be removed as long as you tune it correct.
fuel Supply is what you want to focus on. VOLUME is big, but because of the limited access of fuel into the VE because of small inlet ports (cant do much besides some larger fittings), hence pressure becomes a big factor, to push in fuel.
look up some articles on dual feed setups. KTA runs his yellow truck that way (and clearly has good results). it will allow some extra fuel to flow at higher loads (low case pressure).
you can install a case pressure guage pretty easily (I did mine through my shut of solinoid port). it will allow you to watch the case pressure and see what is happening.
my advice (keep in mind ive never done a 14mm). but anyways... I would run a mechanical rotoray lift pump instead of a electric. (just because of volume). one like this...
http://www.obxracingsports.com/products.php?pk=1555.
rig it up with a pully off of somewhere, a healthy fuel pressure regulator and you will have a BIG reliable fuel system.
only mystery to me is what the 14mm needs at IDLE, because Im guessing the rotary fuel pump would fall to 15-20 psi at idle, unlike a electric that would maintain its high pressure