On my new kits, I like to toss the aluminum ball studs and use the black steel ones. Also, in the steering rack, I use the same ones as the kingpins, since they're long enough to use with 5mm of ackerman and don't bend easily.
The 2pc suspension mounts for the F/R position might be an option if you have trouble bending that piece. Also, the 2pc top deck from the original 416 kit is a nice tuning option if you plan to run on carpet, though lately I've been preferring the feel of the 1pc with the new chassis.
The Parma T2 bumper is almost a direct fit, and requires just a little modification. I hear they may be making a 416 version. Also, I like to run aluminum c-hubs or the IFS (soft) version, as they tend to break easily.