Go spend some time searching thirdgen.org. I think you'll see plenty of people there running at LEAST 12's on the "stock" systems.
Edelbrocks system seems to make its owners happy, but for the cost, I think a semi-intelligent person can do as well with a "stock" setup. Burning your own chips only requires a laptop, cable, PROM and the chip burner, the EEPROM and burner are something like $150, cable can be made for $3-9, and if you don't have a laptop, you can probably borrow one for a few days.
Yes in the case of TPI the long runners really are a restriction up high or on a large engine, but as BurbinOR can attest to, it still works and can make you happy on a larger engine.
As with anything, the injection system needs to be matched to what you want to do. Look at the miniram, stealthram, etc. Even though they are expensive, they will support a much "healthier" engine at a higher operating RPM than the stock runners. Still, I don't think the lowend torque is there like it is with the TPI system, but I couldn't justify the cost for any of those intake setups, so I didn't really research them much.
