The PRO CFW works on all PSP models, and I believe the latest official PSP firmware is 6.60, which means you should be able to hack yours. However, I'm not entirely sure if you will be able to have it as a permanent hack, but as long as you don't turn off your PSP (putting it in standby mode isn't a problem, though), everything should be fine. Not that it makes that much of a difference, as reinstalling the temporary hack is only a matter of seconds.

There's a short, nevertheless useful, installation guide on the Google Code page.

I planned on writing a guide for this ages ago, but eventually ended up abandoning that idea, simply because my guide ended up being more complicated than the 'official' one, lol.