Probably a bit late now, but I went for the test last month (and just found out I failed, oh well...) and it's really not a test you can prepare for. The psychometric test part is just about logical thinking and following instructions rather than numeracy, so you need to work quickly and get as much done as possible, but it's not a maths test like SHL. And the written bit just depends on how well you know the general things like inflation, GDP and so on, and then apply them to a particular situation that they tell you in the instructions. So it's more about being generally good rather than something you can research/prepare for in a few days.