Fuel pump for boost

ok guys with the new mods to my car i'm gonna be ready to turn it up, now i need to work on the fuel side of things and i have noticed that everyone seems to go with a new fuel hat which can hold multiple pumps. The price for this is not cheep but with all the options i'm hoping i can save a few bucks and just upgrade my pump with the walbro 450 and do a external in line pump on a hobbs switch to supply the extra fuel. I haven't seen anyone do this type of setup but was curious if as to why or am i missing something?? I do plan on upgrading the 65lb injectors to something bigger along with bigger fuel lines. I can add a external pump way cheaper than buying a kit from one of the multiple dealers around, just looking for options.