Unless you have a ton of space, I would recommend some kind of variable weight dumbells, such as Bowflex (high end), Powerblocks (mid-end) or Reebok (low end found in Target). If you don't want to spring that much money, you can do almost all exercises with a set of workout resistance bands.
The heart rate monitor is nice to make sure you don't go overboard, but not absolutely necessary...got mine at Circuit City (Timex),
the push up bars only if you want to go deeper in your push-ups or if you have wrist issues, can get these at Target
the pullup bar is a must, if you don't get a door mounted one, if you are handy you can hang a steel bar between two rafters in an unfinished room, you can also use the exercise bands for this too...actually bought this at Beachbody and it has been very sturdy...
I would get some 1% Chocolate milk you buy at the store for a recovery drink, it is just as effective, but has no creatine...if you want that boost, try the Fruit Punch mix you can get at Target, but you will have to add some fruity flavor of whey protein or Twinlabs Aminofuel
For any supplements, go to Vitacost.com...much more cost effective than Beachbody or GNC...
Living it- P90X grad- Cycling through again!