I don't know how much memory the final design will need, but at the start if we want to just use the MSP430 as a glorified USB to Jtag adapter the current part should be fine, if we wanna say load the bitstream and everything from the uC, I don't think it'll be a good idea, we should just leave that for the motherboard design stage.

Basically I don't see a need to move to a bigger/more powerful MSP.