You're in the supercharger forum.
The best power adder out ther is an intercooled supercharger or turbocharger upgrade. You won't ever come close with all the available non-blown upgrades to a positive displacement solution.
For a mild Lightning intercooled/supercharger transplant upgrade, plan on about $3k. This will take you from the stock 225rwhp (est) to around 350rwhp while still using the stock block.
2001 F150 Supercrew XLT 4x4, White
Factory Tech 4R70 Monster Box Transmission, Total Domination Torque Converter
Forged/built 5.4L engine, performance heads
Whipple @ 16psi
60# injectors, SCT BigAir MAF, Accufab TB
AFCO heat exchanger
Dual SVT Focus fuel pumps (Lightning fuel assembly & hi/low voltage control)
Fabtech 6" lift
Fox Racing triple front shocks
National Spring Co. custom rear leaf springs
35x12.5R17 Procomp Xterrain tires
17" Extreme Alloy rims
500HP, 550ft-lb torque