I'd replace the CPS and keep the existing as a backup. I'd buy a spare Standard Motor Products RCM to keep in the car as that can be swapped out without tools if you get stuck somewhere. I'd also buy and keep a spare Cam Shaft position sensor on hand. Has it ever had the brake fluid and coolant changed? If not I'd do those right away as you don't want the engine and brake system rusting and failing from the inside out. I'm personally not a fan of going crazy with preventative maintenance when it comes to replacing perfectly good working parts. Going down that road it's very easy to end up with a trunk or garage full of perfectly good spare parts and an empty wallet or purse. As another posted... DO THE STICKY KEY FIX NOW as if it hasn't been done it's just a matter of time for most before that ignition is gonna give you problems and it can be a big PITA if it locks up to the point you can't turn the key. Video on Sticky Key Fix... 40k views of this video says it all.