How large can you go when boring out stock 2.0L cylinders? And what pistons would work at that size? If you kept the stock rods, what would the new displacement be?

96mm, use KB pistons, stick with a proven combo.

with custom pistons you could go to 98MM but it would cost quite a bit.

with 96mm it would be 2056, and like mark said its a common combo, proven to work well, but you will need to get your MPS adjusted.

rich