About chest injections, I've been doing it for B-12 just to give enough sites for ed rotations. Go in carefully with a 1" pin into the middle meaty part if you have to. I personally like it because I can use both hands and see it clearly, but I don't believe in site injections that much so I doubt I will do it for real gear. Maybe I'll change my mind when I fondle my winny amps...
As for upper chest, I jumped to look at this thread. See, out of every part of my body, I would say my upper chest has always been the best part proportionally. It is always square, always pumped, and carry good size in spite of everywhere else that may be lagging. (My lower and outer chests are a different issue.)
What is the secret? I think genetics play a huge role. I can't get the seriatus (sp?) muscle strips around my ribs for the life of me. It's also very difficult for me to develope lower lats. However, upper chest is simple. I think incline db press will worker as well for you as stiff arm pullovers work for me (for the rib muscles). Meaning, they'll do something, but you can't help your genetics. Also, try starting your chest day with incline. Six years of training never did it different.