5.7 hemi into an A-body?

I want to see a twin turbo 6.1 hemi. If they can get LS series motors with twin turbos up into the 1000hp range, i dont see why the new hemi couldnt get that.
As far as these engine becoming the new swap of choice, they will within the next 10 years become lots more common with rodders. I think getting the factory computer with one of these pulled engines would help save some money in this swap, and even though its time consuming, a person could sort out the wires for these engines and such. with that, all youd need is a gas tank with the pump inside, that is, if you wanted to go EFI. Otherwise maybe in time we'll see a cheaper carberated set up..
Speaking of gas tanks and EFI stuff, what does "returnless" mean? I thought with fuel injection you needed a return line for gas that wasnt used, ive read returnless somewhere when refering to a certain EFI system. Im new to alot of stuff, old and new and need help sometimes understanding.