How to increase fuel volume w/s14 tank?

[D1S13]

Going to run e85 w/1000 cc injectors- looking to increase stock fuel line to -6

I know the issue of increasing fuel volume/press has been solved by running dual walboro's on the s13 since it has a metal cover to weld -an to it.

However the s14 gas tank cover is plastic.

Question: What options should be considered to increase fuel volume with an aftermarket fuelpume when using s14 gas tank?

Suggestions so far- external fuel pump (But this car will be daily/regularly driven- not sure if external pump would be a good idea).

Any other suggestions?