In tank pump or external reservoir would be un needed plenty of injected cars run inline pumps,Porsche Audi,VW ran injected cars from the late 60's until at least 2000 when I quit working on them.The guys doing Buick 3800's into fieros are running an inline pump. You will have to research which pump has correct pressure,volume and line configuration for your project but still a simple deal.
I'd prefer to do the inside tank option to stifle pump noise, but I haven't been able to source the sending unit that came in the efi trucks yet. It would be fairly easy and simple to add one inline. I just don't want the noise associated with the external pumps.