In tank fuel pump ideas/suggestions for Ram Jet 350

[GM man]

My original 350 has a little over 450k miles on it and is in need of a long rest. I'm thinking that I'm gonna replace it with the Ram Jet 350. I know GM recommends using an in tank fuel pump, so I need advice on the best way to accomplish that. Is there a tank from another vehicle that would work for this or is there a good way to retro-fit a fuel pump unit in the factory tank?? And,...has anyone seen or heard about anyone using a small fuel cell (like a 5 gallon), mounted in line with the factory tank that could house the fuel pump and serve this purpose??