If you're going to use any injectable gear, then of course you're going to need some "darts." You can pick up syringes at your local pharmacy unless your state has certain restrictions. Also, you can purchase needles online. Just do a little searching around and you'll find several places that'll hook you up. Syringes will run you around 50 cents apiece. Note that it'll be more difficult to obtain needles (at least from the larger, more "legit" companies) if you live in California and Illinois. You'll usually need a doctor's prescription in those states. Still, if you look around enough, you can get what you need.
HCG is a highly beneficial hormone in fertility stimulation and in the treatment of low testosterone. In fact, it is rapidly becoming an integral part of many low testosterone treatment plans. For the anabolic steroid user, the performance enhancing athlete, HCG can be beneficial but it can also be damaging. Many get very carried away with on cycle use and lead themselves to an early low testosterone condition. Granted, most men will benefit from testosterone therapy at some point in their life regardless, but many steroid users end up requiring sooner and often due to improper HCG use. The hormone can be beneficial but use must be kept moderate and monitored.