JB weld. That's what i did. make sure you clean the holes up well for the JB weld to adhere correctly. Sand smooth with a die grinder.
You will end up with a shit flat spot below 3000rpm, but can be tuned out via remapping the rom in the ecu.
As for your other questions, forged rods are available through different manufacturers, however your question on machining is like asking "how long is a piece of string?". Be more specific.