Forget running multiple pumps. Injector Dynamics FPS1100. This pump and the driver can go up to 2000whp on E85 and 3000whp on race gas from a single pump.
FYI don't be too stringy about the second pump coming on, if you try to bring it on with pressure already present it'll "be slower" to contribute. So if you wack it in 1st it may not actually come on in time to prevent pressure dip.
ID FTW! Great comparison of one companies misleading marketing of an off the shelf injector that under performs its proclaimed rating versus a purpose built motorsports injector with an in house built valve and magnetic pole for truly improved performance, flow rate, and data. ID is the gold standard, made in partnership with Bosch not just bought from Bosch.