Yeah the Baby GMs use an 8 cylinder while the F7s had a 12 cylinder engine. But I don't think there is much difference sound wise. Digitrains in the UK sell a Tsunami with the 567 sound on it but since it's US outline the other sounds won't be prototypical. But you can choose from 16 different horn sounds so you may well find one that is close to an Irish sound.
ESU have downloadable sound files on their website, they have several generic US files including a couple of 567 prime movers as well as the 071 and 201. You can listen to samples on the website and they sound pretty close to a Baby GM. These can be loaded onto any Loksound decoder if you have a Lokprogrammer which can be got for around €150.
I was also onto Olivia's Trains in the UK and they can load any of those sound files to a decoder for you. Furthermore, they can mix and match sounds from other files. I was asking them could they take the 071 or 201 sound file and replace the prime mover with the 567 and they said it was no problem.
But as I said, if you buy a Lokprogrammer you can do all this yourself!