I sell pretty much everything for all toyota V6's
There have been no real high power stock bottom end 5vz-fes out there...most speculate that the rods are good to around 400-500whp while others have already tested them to the 400whp mark already with no problems. Nobody wants to push the envelope just yet on a stock motor.
If you need rods yes i do carry pauter rods and they will take you to 300hp PER CYL

same for the pistons.
If you wanted a standalone too i work with the hydra ems which is 90% plug and play with the 5vz (not 100 just because its not installed in the ORIGINAL vehicle

so some wiring is still needed)
How much PSI you looking to run? Just determines the CR of the pistons that you will need.
I also can get regrinded performance camshafts, valves, valve springs...soon headgaskets as well.
The 3.4L would yield HUGE results because of the displacement...i love the 5vz-fe to death :P