that's a v good deal.. I am quite sure it'd work in the Z since it works with a 6GB microdrive and thus should support the block capacity, which will be a limit of the kernel driver... however, when talking about a kernel which Sharp have played with you can't be too sure, so I would say with OZ and pdaXrom I'd say 99.999% certain it'd work, with Cacko 99% and with Sharp only 97%.
If newegg would accept my credit card and guarantee delivery by Saturday I'd buy one!
--edit - that is to say, not being a resident of USA and my credit card being from UK, it's unlikely they would.
anyway, the good thing is it won't be long before prices will catch up in the UK.