Schnordle, I can confirm that arginine is effective and have experienced greatly improved morning wood from it. Kingpole says the ketoglutarate form is better, and arg. ketoglutarate is cheap enough at Wal Mart. I have asked him if I can post his full reply.
Unfortunately these supplements are about 6 times the price here; we pay $30 for about 3 ounces of glutamine powder, which costs about $25 a pound in the States. From my searches these are economical outlets, but I can’t vouch for their reliability or service:
Arginine (both forms) look fairly affordable here:
Do a search for the specific supplement, as some items do not show up in the lists by category.
If you read the threads on arginine supplementation, you will notice that you need to take a significant amount daily (e.g. 5 - 10 grams) for a week or two before the effect cuts in. Arginine is a vasoldilator so you may notice the effect on your blood circulation as well as your erections.
Also make sure you are getting enough sleep and giving your dick enough recovery time from your PE workouts.