I'm assuming you're not from the US since we never got a 1.6 here. One of the more utilized options like that here, is putting a 2.5 block under our stock 2.2 heads. This garners up a lot higher compression ratio, and around 200hp at the crank if done right. It's a good amount of work to do, but not as bad as a swap. I don't see why you couldn't put a 2.0 block under your 1.6 heads and have a similar result as far as power over stock.