The P90x workout site. If you mean for free, no. How else do you expect them to scam money out of you if it isn't through buying their extremely overpriced, crappy programs?
No idea but I do an 'Insanity Fitness' class before boxing on mondays, and after on fridays. It's great, although our coach does make it harder for us boxers....so it's probably not the same
If you have a Droid phone you can get a list of all of the p90x workouts ...aps called 90droid I think
Just make your own up. It's just resistance based cardio. You could do a standard strength routine(Squats, deadlits, ohp, bench, pull ups) and keep the weight at something manageable and do high reps/intervals or something.