I used to run the exotek battery strap but i think you are limited on where you place your battery, you may be able to modify it but i think the stock strap and either stock battery tray or aluminum battery tray are the best methods and easiest to use.
For the steering rack i would just replace it with a stock steering rack, the aluminum racks can have binding issues so better to just replace the worn one with the stock replacement. Its ok if they get some slop, they should last for a few months with regular use. I replace mine about every few months unless it starts binding.