At long last, aftermarket rods are available for these massive Toyota engines! BC calls these their PRO-H rods (H-beam), and they come in 2 flavors.
For most builds, the 2k version is all that's needed. The ProH2K is rated in excess of 1400 HP and priced for the everyday performance enthusiast who isn't going to the moon, using ARP2000 rod bolts.
Anyone looking to pump it up to the next level would want to opt for the ProH625+ version, which uses Custom Age 625+ fasteners instead of the ARP2000s. They cost a bit more, but they're rated at 2000 HP and should be able to handle anything you can throw at them!