I am planning to acquire spare cam and crank position sensors for my new to me 37K Coupe. Prior ownership dealt with SKREEM and RCM fix, and I/they believe position that sensor replacements were done but cannot verify whether BOSCH parts were used.

Question is whether it is worthwhile to have a spare RCM on hand, and whether I should stockpile any others in order to minimize down time/getting stranded. And also which retailer is recommended for these parts?