blah... done it!
If your going to Ibiza, you should give yourself at least a week and be prepared to spend at least £1000 in total.
You should be able to find the chepest deals for flights and accom together on either www.lastminute.com
We used www.lunnpoly.com but weren't impressed with their organising or service, fortunately the clubs, DJs and sun made up for it.