I suspect the PPL books are worth owning as a future reference anyway. You can also write or take notes on your own copies, so that's worth considering too!
In terms of block booking, I've seen plenty of schools offering this (I'm still deciding where to go myself for PPL) but the one piece of consistent advice that every single person I've spoken to in aviation has given is not to pay any large sum up front. It seems that flying is an expensive business and schools go bust all the time, leaving people high and dry (and penniless!)
EDIT: I suppose if you have to pay some money up front, it would be sensible to pay on a credit card (assuming Ireland has similar consumer credit protection that the UK does) and use the hours as quickly as possible, perhaps limiting to small blocks at a time?
Hope that helps as a quick reply. I'm sure someone who actually knows what they're talking about can offer better advice shortly...
