As always, just my opinion on things.
If you are looking for something to take before work, drink a whey shake (try buying a tub of
natural whey powder, then just drink as instructed); if you want something during work, drink a whey shake; if you want something after work, drink a whey shake.
Proprietary products that claim to enhance the amount by which you "buff up" (or any other unreasonable - as defined by realistic expectations - claims) are almost, without exception, full of crap.
The best thing you can possibly do for yourself is create a consistent and balanced diet of healthy foods, thus supplying your body with all the protein and carbohydrates it will need to take full advantage of the work you are doing. Also, create a fitness regime which incorporates cardiovascular activity (in case you feel you are not getting enough at UPS) - just focusing on "getting ripped" is not a good idea, for what it's worth.
Another good (in my eyes, anyway) tip is to not eat three square meals a day, as is the conventional wisdom; rather, eat six to seven smaller meals a day - this keeps blood sugar spikes to a minimum, ensures a healthy flow of nutrients to your body, raises your metabolism, and lots of other good things.
A good rule of thumb: never pay for anything that claims to help you lose weight, gain muscle, or both. Working at UPS and moving heavy objects for 3.5 or more hours a day is part of the equation of gaining muscle/strength; the other half is the hard part - eating healthy foods, not drinking or doing any drugs, consistently refusing to go out bar hopping (because a hard night of drinking will destroy a week or more of hard fought gains), and other "common sense" things.
Consider reading about the technical difference between
muscle hypertrophy and
strength training.
I won't plug any pay website, but the free one I frequent is located
here; I'm not affiliated with it, I just find it to be honest about what to expect when attempting fitness of various intensities.