Im sure you can get bluefin for VAG, alot of the 8P boys have this, so maybe worth having a look in there..
As for upgrading the 1.8, you aint really going to get much power gains from a chip, If it was me personally, I would save the money and see if you can add some more to getting a better looked after 1.8T, as it sounds like thats what you are really after and once you find a decent one, put the money into that and have instant and more noticeable power gains.