Get the racetronix in-tank kit. It should be up for the task, it is easy to install, and comes with everything you need. My car was dropping down to 40psi on the bottle at only 6000 rpm, but now only reaches a lowest of ~52-54 psi at 6500 rpm. At idle and cruise it now sits at 62 psi.
When I first hit it there is still a very fast drop in pressure that literally lasts 1/2 a second or less. It comes back up to 62 right away and slowly drops to low to mid 50's by the time I shift.
06 Silverado Limited Edition
04 GTO M6
ASP Crank Pulley
02 Formula M6
Whisper Lid, TNT 125 Shot, S2, Hooker Long Tubes, Custom Duals, ASP Crank Pulley, RPM2 (232/236 .574/.577 112), ARP Rod Bolts, Racetronix Fuel Pump System, B&M Shifter, SPEC 2, 8.8" Rear With 3.90's, BMR SFC's, BMR LCA's, BMR STB, Chrome Z06 Wheels