As Naryar said, you can use a Stock AI bot's chassis to get more HP but it doesn't really help as much as you would think because you are left with quite a bit of empty space in the chassis. There is a reason that people say to build the bot around the components.
Also, unless I modified the version of Emergency that I have on my Mac, it has standard steel armor. I think I have a list of all of the armor types used by the stock AI somewhere on my gaming PC...