HGH will work the same with whatever needle you wish to inject it with. For me, since I am giving myself two shots a day, I am interested in the smallest needle that will get the job done. There is no advantage to a larger needle, there is more chance for causing scar tissue, and when injecting into the muscle you give up the slight localized fat loss benefit that is possible by injecting Sub-C into the stomach, obliques, fronts of thighs, etc.
If you were talking about injecting IGF-1 or LR3 IGF-1, then it is beneficial to inject directly into a muscle that you just worked. In that case there IS a localized assist with muscle growth, and the stress caused by working out a muscle increases the number of IGF-1 receptors in that muscle.
HGH doesn't have a direct localized muscle growth affect. It assists with muscle growth by shuttling nutrients to the muscles in a very complimentary way to insulin, and also by getting processed through the liver, with the liver secreting IGF-1 as a result. These two actions are what assist with the growth process, not the HGH having a direct effect on the local muscle.
As far as taking GH pre or post workout, that is really a tough call. There is merit to both ways. HGH takes about 3-4 hours to be completely absorbed and processed. The result at completion of processing is a bump in your IGF-1 level. In a perfect world, if you could time the increased IGF-1 level with the increased IGF-1 receptors in your muscles, you would in theory get maximum benefit that way. The reality is that it would be very difficult to precisely do that and also being on several units of HGH 5-7 days a week maintains a sustained IGF-1 level that is well above normal anyway. Also, since HGH shuttles nutrients to muscles, there is post workout benefit to this, but there is also benefit to having the muscles topped off before really hitting them as well....so I would say there is no definitive answer to this.
The general advice I typically offer is that you take 2-2.5 IU's of HGH first thing in the morning when you wake up and then another 2-2.5 IU's of HGH in the early afternoon. This is the general time when your cortisol levels are at their highest, and HGH will assist with keeping the potential catabolic effect of cortisol on your muscles to a minimum. This is probably the best option with regard to HGH timing....It also allows your body to release the nightime pulse (the biggest of the day), so you are getting your own release of HGH in addition to the units you are injecting.
Hope this helps some.
RedBaron