I'm not sure what injectors are hard to come by, haven't heard that one before. Aside from keeping the fuel clean and not tuning it there really isn't anything to worry about with the injectors. When they fail, they fail. Buy them when you need em, as it's not a side of the road job.
Here is the maintenance schedule I follow.
Oil/Filter Change 7500 miles
Fuel Filter Change 10000 miles
Tranny Service 30000 miles
Differential Service 30000 miles
Just out of curiosity, what front end work did you have done. I'd love to get my front end handling better as their is too much clunkiness.
Thanks!