pizza-dude- According to Walter Henderson of AE-the narrower you get them-the better he likes it. And in stock he doesnt think a top plate is neccessary-even with batteries moved all the way in to driveshaft. I am putting a top plate in anyways because I want to cut off even more of the chassis in a few spots that will hurt rigidity.
James Nguyen- For stock-I would just buy the IRS lightened input shafts and if you need to run a transponder-get the IRS servo/transponder mount. The rest of the stuff you need to do is all labor intensive. Lots of cutting on the chassis-though not neccessary to dominate with car!!