Dude,
Rather than risk making a mess of it I'd get Mr Valenti to make a parts bass for you.
Check out >>
www.valentibasses.com , he's also a regular on talkbass.com, there's a few threads on here with some awesome looking basses.
His basses get amazing reviews from all the talkbass members who own one, apparently giving much higher priced Sadowsky and Lakland basses a run for their money, and with todays exchange rate an Active 4 string P Bass comes in at €1,124.62, just a wee bit over your rough budget.
Cheers,
Eude