You may want to look into getting the rear brakes/disks/calipers from the junkyard. '05 fronts were running about $30 in my area, so you could probably pick up everything you need for maybe $200? As to other information on what the SVT brake kits come with, check with Leo Capaldi ("LCR"on this board) as he's a site sponsor and the series director.
Brake balance is pretty good, but go with the most agressive rear pads you can find. Every little bit helps for turn-in. You'll still have to trail brake the crap out of the car to make it turn, though. It almost has to be pitched into the corner rally style.
Most of the cars have the battery relocated to the tire well. However, you may want to look into one of the lighter weight batteries such as the oddyssey brand, as getting the car down to weight is going to be a challenge. If you want to be at the minimum (2650 with the 2.3), you'll need to pull the windows and window lifts off the car as well as anything else you can find. AC, and maybe even the HVAC system. The oddysey that I have (sorry - forget the model - 680 maybe?) weighs about 12 pounds vs. the 30+ for stock. Plus it's a gel model so you can mount it in any orientation.
If you can get 160-165 on a dynojet -you're going to spend a lot of time on the dyno and swapping in exhausts and the like. Strong cars will be mid 150's with just bolt ons. Speed costs money - how fast do you want to go?