I'm not sure what your injector size has to do with it, actually it has nothing to do with it, but anyways, if you are doing an HCI combo, you might as well do all of it at once. Try these:
Trick Flow Twisted Wedge 5.0L EFI Engine Kits: TFS-K514-350370B - summitracing.com
I have this one and love it, I just have the cam that makes 360 hp and 350 tq. I'd go with the 350 hp and 370 tq cam since you get more for the bottom end. I love this kit and TOTALLY wakes the car up.
Holley SysteMAX II Engine Systems for 5.0L Ford: HLY-300-501-1 - summitracing.com
This is pretty much the same thing, just in Holley...
The only other thing I would do is get a new set of FRPP hydraulic roller lifters, since the stockers are probably showing age (like mine)
Ford Racing Hydraulic Roller Lifters: FMS-M-6500-R302 - summitracing.com
Now, it's kind of expensive but once put together and tuned will do wonders for your car.
I know you were asking for intakes, but since these intakes are made specifically for the rest of the parts in the setup, you would be maximizing the setup. You could also take the heads somewhere and have them ported and have the intakes port matched to the heads.
HOPE THIS HELPS!