FPGA evaluation board that can generate/read 1.2V

If I understand correctly, you want 1.2 volt for an IO bank on the device.

Most dev boards I know have 3.3, 2.5 or 1.8 volt IO banks by default. 0.9 to 1.2 V is usually used for the FPGA Core voltage, so it's available on the board (depending on the core voltage of the FPGA) but not tied to the IO Ring.

A few boards have switchable 3.3/2.5 IO banks so that may be a possibility, but you could also use a level translator chip to switch from 2.5 down to 1.2 V on your breakout board.

The schematics for the various dev boards are available on-line, so you can check the schematics to see what is driving the various bank VCC's and then see if it will fit your needs or can be hacked to fit your need.

Pete