Try SUB-20 SUB-20 Multi Interface USB Adapter USB to I2C SPI GPIO RS232 RS485 Ir
It has 2 MDIO channels. One is CFP compatible running at 1.2V with 4MHz MDC frequency.
SUB-20 has integration modules for LabView. Low price, good support, reliability. What else?
We use SUB-20 as I2C master as well and also via LabView module.