ETOPS - it might be a little difficult to do an assy procedure in a single, but if you succeed it will impress the hell out of the examiner
Definitely worth getting down to your local club to do some IR work, even on the singles, as making your calculations for flying each procedure in the air has no comparison to doing it in a nice warm chair in fornt of the PC. Best revision you can get I reckon.
As for the test, everything you need to know is here aleady. Biggest problem is the pressure you put yourself under to pass because of cost etc. Constituent parts are all fairly straightforward, but after 2- 2.5 hours it doesn't quite seem that way.
Hope it goes well for you.