Rightio, time for an almighty bump. I plunged ahead and bought this and I must say I'm mighty impressed.
It cost €670 which is around AU$1000/£570/US$750 and came from a guy in Greece. You can save a bit if you are prepared to ship your current F1 wheel to him, otherwise he'll buy you a new one to mod.
The quality is good, and the buttons and switches feel a lot more stronger and durable than the buttons on the original F1 wheel mod. The price also includes a SLI Manager license for the LED lights thingymabob (I'm not technologically gifted).
An extra USB cable is needed for the extra switches and the LED lights which is probably under a meter in length, that can be a downside if your computer tower is a long way away from your seat.
The negatives are minor. There are still stickers on the buttons, which I do feel will come off after repeated use but so far (about 3 months) I haven't had any issues with that. The guy - although friendly and helpful - obviously doesn't have English as a first language, so things can get somewhat lost in translation. For example, he said once payment had gone through he would start on the wheel straight away, but what he meant was he would order the parts straight away and that will take a couple of weeks before he can start on the actually construction which will take another few weeks (naturally). In all it took about 8-10 weeks to arrive, which got me a little worried as to whether he'd just taken my money. In saying that though, he answered all emails promptly and quickly which helped allay my fears.