Transmission skid plate is a purchase-able part, right? Just bolt on?
Best to start a new thread so information is somewhat easy to find. But to answer your question. the front Skid is bolt on, it just won’t work with KDSS which on SR5's it’s not an option so no worries. The Locker rear diff. Is certainly not a requirement to going off road, helpful in certain situations yes but knowing how to drive and a good set of aggressive tires would do you more good than a locking rear dif. If you get to the point where you want one ARB makes air lockers for the front and rear that are equal to, if not better then the factor E-Locker. Your SR5 is more capable than your driving ability at this point ( I am saying that with no offense meant)