hey bambu. you've helped me a lot in these recent days regarding contacting surgeons, and a plethora of other useful information, so as an amateur bodybuilder by hobby, here's my two cents.
i started lifting weights at the age of 17, i am now 19.. and i think at this age, i shouldn't (and i realized, that i did not) have any issues with testosterone levels. i started working out without any supplements, and packed on muscle just fine.. however, in january '04 i started taking a protein shake right after my workout.. that helped a LOT.
at my gym i've seen people who have gotten into lifting weights after they are 40 + ..... and they're doing fine! even though their testosterone levels are where they were 20 yeears ago, with a proper diet, in addition to proper training, they're doing great.
personally, i would recommend 'whey protein' to just about anybody. first of all its 100% natural (extracted from cow's milk, and its one of the best, might even be the best, protein out there.) i would recommend that you get Whey Protein from 'Muscletech' its called "Nitro-Tech" i believe it is the best whey protein in the market; on side note, it is more expensive than the other ones out there. i have used whey protein from Ultimate Nutrition, Optimum Nutrition, Pro Lab, and our canadian brand called 'PVL'... everybody keeps on talking to me about Nitro-Tech and i have seen the results on a few friends.. I'm waiting for my 5 pound contianer of protein to get finished, after which i'm switching over to nitro-tech.. either way, whey protein (be it from Muscletech, or GNC) will do anybody who is planning to put on some muscle, very good.
i have read about your very very busy work shifts.. how often do you get to work out? 3-4 times a week would be perfect actually.. make sure you take 1-2 scoops of whey protein right after you work out.. usually you can mix it with water, but personally - if you mix it with skim/2% milk it usually tastes wayy better (pretty much like chocolate milkshake).
a lot of packign on muscle is purely diet-oriented. eggs are really good for putting on muscle.. and if you're not looking to put on an unwanted poundage (as in fat) then concentrate on eating lean protein, such as skinless chicken breast, lean turkey, lean beef.. eggs. and don't completely eliminate the carbs, proteins are the building blocks of muslce but carbs are the stuff that actually do the building..
theres a lot of pills/other supplements out there. however i don't see the need to take anything else than whey protein.. you could try creatine cycling.. or take amino acid capsules (Max Fuel, by Ultimate Nutrition) - that will help you in muscle recovery.
but yeah, those were a few thoughts on supplements.
one thing that i would highly recommend is Arnold Schwarzenegger's "Encyclopedia of Modern Bodybuilding"
its the most comprehensive bodybuilding encyclopedia.. i hear sylvester stallone has published his bodybuilding memoirs called "Sly Moves" - planning to get a copy of that sometime soon.
hope this helped.