Since TRANSPORTPI MKII accepts I2S input it should work. There is also a MCK input but I don’t know what frequency is suitable for this input, you should ask the designer. BTW, the FIFO Lite provides MCK output at the frequency of the connected oscillators.
We are working on the Sonic Empire DAC but it will take long time to get it ready, at least one year, maybe more.
In the meantime I would suggest to get the DAC Lite running and compare it with your ABBAS DAC driven by Ian’s SPDIF transport.